ToolnozaMath & Date Calculators
How to Calculate Age on a Specific Date
Calculate age in completed years, months and days, and understand month-end birthdays with a worked example.
Practical guides for your files, images and workouts
Concrete steps, examples and limits to check before downloading your result.
101 guides found
Math & Date Calculators
Days Between Dates: Inclusive vs Elapsed Counting
Learn when to include both dates, convert a duration into weeks and avoid confusing calendar days with business days.
Math & Date Calculators
Image Aspect Ratio and Matching Dimensions
Reduce image width and height to a ratio, calculate matching dimensions and choose between cropping and resizing.
Math & Date Calculators
Percentage of a Total vs Percentage Change
Choose the right percentage formula for shares, discounts and increases, with three worked examples.
Social Media Tools
Create a QR Code and Test It Before Printing
Turn a URL or short text into a downloadable QR code and check the destination, margins and final print.
Unit Converters
Convert km/h, mph and Metres per Second
Use consistent conversion factors, check a worked example and avoid confusing speed with running pace.
Math & Date Calculators
Add, Subtract, Multiply and Divide Fractions
Use common denominators correctly, simplify answers and check why a fraction denominator cannot be zero.
Unit Converters
Convert Square Metres, Hectares and Acres
Convert a known area without confusing square units with length, using land-area examples and sensible rounding.
Image Tools
Flip an Image Horizontally Without Rotating It
Choose a horizontal or vertical mirror, preserve the framing and check text before exporting your image.
Image Tools
JPG to PNG: Quality, Size and Transparency
Convert an image format while understanding file size, existing JPEG artifacts and transparency limitations.
Mining & Quarrying
Excavator Productivity Calculator — Calculation guide
Estimate excavator cubic metres and tonnes per hour from bucket size, cycle time, fill factor and job efficiency.
Industrial Mechanical
Equipment Availability Calculator — Calculation guide
Calculate equipment availability, operating hours, MTBF and MTTR from scheduled time, downtime and failure counts.
Electrical & Lighting
UPS Runtime Calculator — Calculation guide
Estimate UPS battery backup hours and minutes from battery voltage, amp-hours, count, usable capacity, efficiency and load.
Electrical & Lighting
Solar Panel Tilt Angle Calculator — Calculation guide
Estimate a simple fixed solar panel tilt from latitude and an optional seasonal adjustment.
Mining & Quarrying
Haul Truck Fleet Sizing Calculator — Calculation guide
Estimate the number of haul trucks needed to meet an hourly tonnage target using payload, cycle time and efficiency.
Unit Converters
How to Convert Text to Handwriting: PNG Notes and Quotes
Turn typed text into a handwriting-style PNG with a calligraphic font, ruled paper, adjustable size and ink color. Preview locally.
Developer Tools
How to Create an HTML Table with Accessible Headings
Build an HTML table online with a caption, column headings, editable cells and spreadsheet paste. Preview and download responsive HTML/CSS.
Developer Tools
Animated CSS Gradients: Colors, Keyframes and Reduced Motion
Create a three-color animated CSS gradient with angle and speed controls. Preview, pause, copy CSS and respect reduced-motion preferences.
Unit Converters
Thermal Conductivity Units: Convert W/m·K, BTU and kcal
Convert thermal conductivity between W/(m·K), mW/(m·K), W/(cm·K), BTU-based units and thermochemical kcal with clear unit definitions.
Text Tools
How to Count Word Frequency and Interpret Keyword Density
Count word occurrences and percentages in text. Filter words, adjust case sensitivity and minimum length, then download every result as CSV.
Pet Tools
Dog Years to Human Years: Formula, Examples and Limits
Calculate a medium-sized dog’s human-age equivalent. Understand the 15–9–5 guideline, months and why multiplying by seven misses early development.
Pet Tools
Cat Years to Human Years: Age Chart and Calculation Guide
Convert cat age to a human-age analogy, including kitten months. See a worked example, chart points and the limits of interpolation.
Pet Tools
How to Calculate Pet Food Cost per Day, Month and Year
Calculate dog or cat food cost from bag weight, price and daily ration. Compare unit prices, bag duration and a 30-day feeding budget.
Pet Tools
How to Calculate Aquarium Volume in Liters and US Gallons
Calculate rectangular aquarium capacity from internal dimensions. Account for water depth, substrate displacement and cm-to-inch conversion.
Pet Tools
Dog Calorie Calculator: Estimate Daily RER by Weight
Estimate a dog’s resting energy requirement (RER) in kcal per day, see the formula and understand why RER is not a feeding prescription.
Pet Tools
Cat Calorie Calculator: Estimate Daily RER by Weight
Estimate a cat’s resting energy requirement (RER) in kcal per day, with a worked example and clear limits on using calorie figures for feeding.
Pet Tools
How Much Water Should a Dog Drink? Daily Estimate by Weight
Estimate a dog’s broad daily water requirement by weight and learn why diet moisture, weather and health change the amount it drinks from a bowl.
Pet Tools
How Much Water Should a Cat Drink? Daily Estimate by Weight
Estimate a cat’s broad daily total-water range by weight and learn how wet food, environment and health affect drinking from the bowl.
Pet Tools
Dog Food Calculator: Convert a Calorie Target to Cups per Day
Turn a veterinarian-approved daily calorie target into cups per day and per meal using the food’s kcal per cup.
Pet Tools
Cat Food Calculator: Convert a Calorie Target to Cups per Day
Estimate cat food portions from a daily calorie target, food kcal per cup and number of meals, with clear assumptions and label checks.
Mining & Quarrying
How to Calculate Circulating Load: Formula & Example
Calculate grinding-circuit circulating load, total mill feed and the recycled share from dry-solids flow rates.
Mining & Quarrying
How to Calculate Mill Critical Speed: Formula & Example
Estimate theoretical mill critical speed and operating RPM from internal diameter, grinding-ball size and selected critical-speed percentage.
Mining & Quarrying
How to Calculate Hydrocyclone Cut Size: Formula & Example
Find d50 or corrected d50c by log-size interpolation between measured hydrocyclone partition points.
Mining & Quarrying
How to Calculate Slurry Density: Formula & Example
Calculate slurry density and solids volume concentration from mass concentration and material densities.
Mining & Quarrying
How to Calculate Crusher Reduction Ratio: Formula & Example
Calculate F80/P80 reduction ratio and particle-size reduction from consistent feed and product size measures.
Construction & Civil Engineering
How to Calculate Welding Wire Consumption: Formula & Example
Estimate deposited weld mass, solid-wire consumption and purchase mass from weld area, length and deposition efficiency.
Construction & Civil Engineering
How to Calculate Welding Travel Speed: Formula & Example
Calculate welding travel speed in mm/min and inches/min from weld distance and arc-on time.
Engineering Tools
How to Calculate Hydraulic Accumulator Sizing: Formula & Example
Estimate gas accumulator nominal volume for a required fluid delivery between minimum and maximum pressure.
Engineering Tools
How to Calculate VFD Energy Savings: Formula & Example
Estimate centrifugal fan or pump electricity savings using speed ratio, drive efficiency, operating hours and tariff.
Engineering Tools
How to Calculate Motor Starting Current: Formula & Example
Estimate balanced three-phase motor running current, starting current and starting apparent power with a supplied current multiplier.
Construction & Civil Engineering
How Much Mulch Do I Need? Mulch Calculator, Formula & Examples
Calculate how much mulch you need in cubic yards, cubic feet or cubic meters. Learn the area × depth formula, bag conversion, waste allowance and a worked example.
Construction & Civil Engineering
How Many Pavers Do I Need? Paver Calculator & Formula
Estimate how many patio or walkway pavers you need from project area, paver dimensions and waste. Includes square-foot formula and example.
Construction & Civil Engineering
How Much Asphalt Do I Need? Asphalt Tonnage Calculator & Formula
Calculate asphalt volume and tons from length, width, compacted thickness and density. Includes Asphalt Institute density guidance and a worked example.
Construction & Civil Engineering
How Many Drywall Sheets Do I Need? Drywall Calculator & Example
Estimate drywall sheets for walls and ceilings from square footage, openings, sheet size and waste. Includes 4×8 example and practical limits.
Engineering Tools
Transformer kVA Calculation: Single-Phase & Three-Phase Formula
Convert volts and amps to transformer kVA for single-phase and three-phase circuits, or calculate amps from kVA. Includes formulas and examples.
Engineering Tools
Pump Horsepower Calculation: Water HP, Brake HP, GPM & Head
Calculate water horsepower and pump brake horsepower from flow, total dynamic head, specific gravity and efficiency. Includes DOE formula and example.
SEO & Marketplaces
Print on Demand Profit Margin: POD Pricing Formula & Calculator
Calculate print-on-demand profit, margin, ROI and break-even price. Learn how base cost, shipping, marketplace fees and ads affect POD profit.
SEO & Marketplaces
Etsy Fees Calculator 2026: Listing, Transaction, Payment & Ads Fees
Understand Etsy seller fees in 2026 and estimate listing, 6.5% transaction, country-specific payment processing, Offsite Ads and conversion fees.
Math & Date Calculators
Calendar Days vs Working Days: How to Count a Deadline
Calendar Days vs Working Days: How to Count a Deadline — Practical steps, examples, common mistakes and FAQs on Toolnoza.
PDF Tools
How to Crop PDF Margins Without Changing Page Content
How to Crop PDF Margins Without Changing Page Content — Practical steps, examples, common mistakes and FAQs on Toolnoza.
PDF Tools
Crop vs Flatten a PDF: Which Operation Do You Need?
Crop vs Flatten a PDF: Which Operation Do You Need? — Practical steps, examples, common mistakes and FAQs on Toolnoza.
SEO & Marketplaces
How to Estimate Website Traffic from Search Impressions and CTR
How to Estimate Website Traffic from Search Impressions and CTR — Practical steps, examples, common mistakes and FAQs on Toolnoza.
PDF Tools
Flatten PDF Forms: Preserve Filled Answers Before Sharing
Flatten PDF Forms: Preserve Filled Answers Before Sharing — Practical steps, examples, common mistakes and FAQs on Toolnoza.
Math & Date Calculators
Mixed Numbers to Improper Fractions: Add and Divide Correctly
Mixed Numbers to Improper Fractions: Add and Divide Correctly — Practical steps, examples, common mistakes and FAQs on Toolnoza.
Image Tools
Invert Image Colors vs Grayscale: What Changes?
Invert Image Colors vs Grayscale: What Changes? — Practical steps, examples, common mistakes and FAQs on Toolnoza.
PDF Tools
Rotate a Scanned PDF: 90°, 180° or 270°?
Rotate a Scanned PDF: 90°, 180° or 270°? — Practical steps, examples, common mistakes and FAQs on Toolnoza.
Text Tools
Sort Lines Alphabetically: Duplicates, Blank Lines and Order
Sort Lines Alphabetically: Duplicates, Blank Lines and Order — Practical steps, examples, common mistakes and FAQs on Toolnoza.
Engineering Tools
WGS84 Latitude/Longitude to UTM: Zones, Hemispheres and Accuracy
WGS84 Latitude/Longitude to UTM: Zones, Hemispheres and Accuracy — Practical steps, examples, common mistakes and FAQs on Toolnoza.
Engineering Tools
How to Calculate Voltage Drop: Formula and Worked Example
Learn the voltage drop formula for copper and aluminum circuits, account for conductor temperature, and check a worked DC and three-phase example.
Engineering Tools
Cable Size Calculation: Find the Cross-Section for Voltage Drop
Calculate minimum cable cross-section in mm² from current, length and voltage-drop limit, then understand why ampacity needs a separate check.
Engineering Tools
Duct Size Calculation: Convert CFM or m³/h to Duct Dimensions
Size a round or rectangular air duct from airflow and target velocity. Follow CFM conversions, a worked example and practical sizing limits.
Engineering Tools
Pipe Pressure Drop Calculation: Darcy–Weisbach Worked Example
Calculate pipe friction pressure drop and head loss using flow, internal diameter, Darcy friction factor and fittings, with a complete water example.
Engineering Tools
NPSH Calculation: Available vs Required Pump Suction Head
Calculate NPSH available from absolute pressure, vapor pressure, elevation and suction losses, then compare it with required NPSH and an entered margin.
Construction & Civil Engineering
House Demolition Cost: Estimate a Budget per Square Foot or m²
Learn how to estimate the cost to demolish a house, separate debris and foundation costs, add contingency and compare contractor quotes.
Engineering Tools
How to Calculate Air Tank Fill Time: Formula and Example
Calculate compressed air tank fill time from receiver volume, pressure rise and delivered airflow. Follow a worked example and use the free calculator.
Engineering Tools
Well Pressure Tank Sizing: Drawdown Formula and Worked Example
Learn how to size a well pressure tank from pump flow, minimum run time, pressure-switch settings and precharge, then verify the result against a manufacturer chart.
Education Tools
Grade Calculator: How to Calculate Your Class Average
Calculate an unweighted grade average, follow a worked example and see when a weighted-grade formula is needed.
Education Tools
Attendance Calculator: Percentage Formula and Classes Needed
Calculate class attendance percentage and estimate how many consecutive classes you need to attend to reach a target.
Education Tools
CGPA Calculator: Formula, Credit Hours and Worked Example
Calculate cumulative GPA as a credit-weighted average and avoid common mistakes with grade-point scales and repeated courses.
Education Tools
Study Hours Calculator: Plan Weekly and Daily Study Time
Estimate weekly and daily study hours from course credits, planned hours per credit and available study days.
Education Tools
Test Grade Calculator: Calculate Your Score and Percentage
Calculate a test percentage from correct answers, convert it to a score out of 20 and understand when weighted grading changes the result.
Finance & Business
Salary to Hourly Calculator: Convert Annual Pay to an Hourly Rate
Convert an annual salary to an hourly equivalent using paid weeks and weekly hours, with examples and clear gross-pay limits.
Finance & Business
Average Down Calculator: Find Your New Average Cost per Share
Calculate a weighted average purchase price after adding units at a new price, including new fees, and see what the result does not mean.
Construction & Civil Engineering
Slope Percentage Calculator: Formula, Rise, Run and Degrees
Calculate grade percentage and angle from vertical rise and horizontal run, with a worked example and the difference from roof pitch notation.
Construction & Civil Engineering
Board Foot Calculator: How to Measure Lumber Volume
Calculate board feet from thickness, width, length and quantity, convert the result to cubic inches and avoid nominal-size errors.
Construction & Civil Engineering
Rebar Weight Calculator: Formula by Bar Diameter and Length
Estimate reinforcing-bar mass from diameter, length and quantity using steel density, with an example and practical ordering limits.
Finance & Business
Reverse Sales Tax Calculator: Find the Pre-Tax Price from a Total
Remove a single included sales-tax rate from a tax-inclusive total and calculate the net price and tax amount with examples.
Finance & Business
Markup to Margin Calculator: Convert Markup % to Profit Margin
Convert a markup on cost into margin on selling price, understand the different denominators and compare a clear example.
Engineering Tools
Water Tank Fill Time Calculator: Formula and Flow Rate Example
Estimate tank fill time from capacity, current volume and net inflow, including an outflow, with assumptions and unit checks.
Construction & Civil Engineering
Concrete Block Fill Calculator: Estimate Grout for Block Cores
Estimate grout volume from the number of blocks, manufacturer core-fill volume and a waste allowance, with a worked example.
Text Tools
Free Resume Builder: How to Create a Resume in PDF or Word
Learn how to create a resume online for free: choose a layout, write clear achievements, tailor your skills and download a checked PDF or Word file.
Health & Wellness
How to Calculate How Many Calories You Burn
Estimate exercise calories from your weight, activity intensity and duration. Follow a worked example and distinguish activity calories from total daily energy expenditure.
Health & Wellness
How to Estimate Adult Height from Parents: Formula and Example
Learn the mid-parental height formula, work through an example and convert cm to feet and inches with clear limits.
Math & Date Calculators
Mean vs Median vs Weighted Average: How to Calculate Each
Choose the right average, follow worked examples and avoid averaging groups without accounting for their sizes.
Text Tools
How to Create Cursive Text for Copy and Paste
Create Unicode script text for bios and captions, compare styles and check readability before publishing.
SEO & Marketplaces
How to Calculate Keyword ROI for SEO and PPC
Model clicks, conversions and profit from keyword assumptions. Compare ROI with ROAS and calculate a break-even CPC.
Mining & Quarrying
Mine Ventilation Airflow: Calculate Q = Area × Velocity
Calculate airflow in m³/s, m³/min and CFM, compare personnel and diesel criteria, and account for leakage assumptions.
Education Tools
Find Least Common Multiple: LCM Methods, Examples and Calculator
To find the least common multiple of positive integers, choose the smallest number divisible by every input. Learn three methods, check worked examples and use the free LCM calculator for exact results.
Health & Wellness
How long does it take for alcohol to leave your system?
There is no universal clearance time. Learn how UK units give an average processing estimate and why that estimate cannot establish sobriety, driving fitness or a negative test.
Image Tools
How to reduce an image to under 200 KB
Choose a suitable format, try a target file size and reduce pixel dimensions when quality alone is not enough.
PDF Tools
How to merge PDF files on your phone
Combine documents in the right order from a mobile browser, without uploading the PDFs to Toolnoza.
Text Tools
How to convert text to MP3 for free
Generate a downloadable MP3 locally, with an honest distinction between browser playback and the export voice.
SEO & Marketplaces
How to choose relevant Redbubble tags for a design
Turn the actual subject, style and visible details into useful tag ideas, then review them before publishing.
Image Tools
How to resize a photo without stretching it
Keep the original aspect ratio when resizing, and distinguish a proportional resize from a crop.
Image Tools
How to compress an image to under 4 MB
Prepare a smaller JPG or WebP for an upload form using a custom file-size limit.
Social Media Tools
How to split an image into an Instagram carousel
Create connected slides from one image, adjust the crop and download the tiles in order.
Fitness & Training
How to calculate barbell plates in kg or lb
Find the load for each side, account for the bar and read the balanced loading diagram.
Fitness & Training
How to calculate workout volume from sets, reps and weight
Track external volume load with consistent units and separate rows for changing sets.
Fitness & Training
How to set up a custom interval workout timer
Configure preparation, work, rest and rounds, and check the full session duration.
Image Tools
Merge Images Online: Combine Photos Side by Side or in a Grid
Learn how to merge images into one JPG or PNG. Choose horizontal, vertical or grid layout, set spacing and download your combined photo.
Text Tools
Speech Time Calculator: Convert Words to Minutes
Use a speech time calculator to convert words to minutes and estimate words to time for reading, presentations and speeches.