Free online calculators and converters for everyday life!
Work out loan payments, solve math problems, convert units, and plan home projects. Find practical tools for finance, health, science, and the calculations that come up every day.
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Calculators and tools
Find calculators, converters, and practical tools to simplify everyday tasks, solve math problems, and plan projects.
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Useful categories
Explore finance, health, math, science, construction, and more—all organized to help you find the right tool.
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Free to use
Use free online calculators and converters for everyday questions, quick checks, and practical planning.
Adjusted Body Weight Calculator
Use the Adjusted Body Weight Calculator to estimate adjusted body weight. Review inputs, results, limitations, safety guidance, and FAQs.
Surface Area Calculator
Find lateral or total surface area for common three-dimensional solids in square units.
Cubic Feet Calculator
Use our Cubic Feet Calculator to find volume from length, width, and height, with conversions to m³, yd³, in³, liters, and gallons.
Mulch Calculator
Calculate mulch volume and full bags from landscape-bed area and the finished depth you intend to maintain.
Protein Calculator
Estimate a daily protein range from body weight, activity and goal for general nutrition planning.
Tile Calculator
Estimate tiles, edge cuts and full boxes using the project size, tile dimensions, grout gap and waste allowance.
Desk Height Calculator
Use our Desk Height Calculator to estimate ergonomic chair height, desk height, and monitor height for sitting or standing work.
Calories Burned Calculator
Use this calories burned calculator to estimate estimated exercise energy expenditure in calories. Learn the inputs, formulas, examples, limitations, training
Running Split Calculator
Use this running split calculator to estimate cumulative and segment times for each split. Learn the inputs, formulas, examples, limitations, training tips, a
Roofing Shingle Calculator
Estimate sloped roof area, roofing squares and bundles from footprint, pitch and a complexity allowance.
Helium Balloons Calculator
Use our Helium Balloons Calculator to estimate lift per balloon, total helium volume, and how many helium balloons you need to lift a given weight.
Theoretical Yield Calculator
Theoretical Yield Calculator to find the maximum product yield from stoichiometry, limiting reagent, and molar relationships.
Dilution Ratio Calculator
Use our Dilution Ratio Calculator to calculate concentrate, water, final volume, or dilution ratio for water-to-concentrate mixes.
Ramp Calculator
Use our Ramp Calculator to find ramp slope angle, grade percent, run, and ramp length from rise, ratio, or accessibility ramp presets.
Image Cropper
Crop JPG, PNG and WebP images with free or fixed ratios, exact dimensions, rotation, flipping and export controls.
Atom Calculator
Use our Atom Calculator to find protons, neutrons, electrons, atomic number, mass number, and ionic charge quickly from standard atomic relationships.
Percentage Increase Calculator
Find the percentage increase between two numbers. Enter original and new values to get % increase, change amount, and final value. Reverse solve from % too. Instant steps & PDF.
Macro Calculator
Estimate daily calories and divide them into protein, carbohydrate and fat targets for general planning.
Power Analysis Calculator
Use our Power Analysis Calculator to estimate sample size per group, statistical power, and minimum detectable effect for a two-sample mean test with alpha and standard deviation.
Gravel Calculator
Use our Gravel Calculator to estimate gravel volume, weight, tons, cubic yards, coverage, and total cost from area, depth, density, and price.
Paver Calculator
Estimate whole pavers for a patio or walkway using actual dimensions, joint width, pattern and cutting waste.
Face Shape Calculator
Use our Face Shape Calculator to estimate your likely face shape from forehead, cheekbone, jawline, and face length measurements plus chin shape.
Variance Calculator
Use our Variance Calculator to find sample or population variance from a data set. Get mean, variance, standard deviation, SSE, range, and sorted values fast.
Cat Age Calculator
Use this Cat Age Calculator to estimate your cat’s age in human years using the common 15 / 24 / +4 cat age chart. Includes formula, examples, life stages, and care notes.
Marks Percentage Calculator
Calculate percentage from obtained and total marks, see marks lost, and compare your score with an optional passing or target percentage.
Free HEIC Converter
Use the HEIC converter below. Check the tool for available conversion options and follow its on-screen guidance.
Plastic Footprint Calculator
Estimate annual household plastic use in kilograms and pounds from common disposable items, frequencies and model item weights.
Triangle Calculator
Solve a triangle’s missing sides, angles, area and perimeter from sufficient known measurements.
Mixed Number Calculator
Calculate with mixed numbers by converting whole-and-fraction parts to improper fractions and simplifying.
Z-test Calculator
Use our Z-Test Calculator to compute z statistic, p-value, standard error, and critical z for one-sample or two-sample mean tests when sigma is known.
Percentile Calculator
Use our Percentile Calculator to find percentile values from a data set with nearest rank or linear interpolation. Supports raw numbers and value:count input.
Punnett Square Calculator
Punnett Square Calculator predicts AA, Aa and aa genotype probabilities and dominant or recessive phenotypes for a simple one-gene genetic cross.
Length Converter
Use our Length Converter to convert metric, imperial, US, nautical, survey, and astronomy units including mm, cm, m, km, in, ft, yd, mi, nmi, au, ly, and pc.
Wavelength → Frequency Calculator
Use our Wavelength to Frequency Calculator to find frequency from wavelength with vacuum, air, water, or custom wave speed. Fast SI-based results online.
Semester Grade Calculator
Calculate a credit-weighted semester grade from course percentages and credits, then compare the result with an optional target.
Speed Calculator
Use our Speed Calculator to find average speed from distance and time in m/s, km/h, mph, ft/s, or knots with step-by-step results.
Commission Calculator
Use this commission calculator to calculate commission earned and combined compensation. Review key inputs, formulas, scenarios, limitations, and FAQs.
Favicon Generator
Turn one logo or image into ICO, PNG and app-icon files with crop, padding, mask and background controls.
Waist-to-Height & Waist-to-Hip Ratio Calculator
Use the Waist-to-Height & Waist-to-Hip Ratio Calculator to estimate waist-to-height and waist-to-hip ratios. Learn inputs, limits, and FAQs.
ml to Grams Converter
Convert mL to grams using ingredient density. Learn the formula, see a practical example, improve kitchen measuring accuracy, and review six helpful FAQs.
Balance Transfer Calculator
Compare a balance transfer’s fee, promotional period, payment plan, and post-promotion APR against keeping the current credit-card balance.
Paint Calculator
Estimate wall-paint quantity from room dimensions, openings, coats, coverage and a practical allowance.
Median Calculator
Use our Median Calculator to find the middle value of any data set. Supports raw numbers, value:count input, sorted preview, and instant live results.
Child Height Predictor
Use the Child Height Predictor to estimate an adult-height estimate for a child. Review inputs, results, limitations, safety guidance, and FAQs.
Free SVG Converter
Use the embedded SVG converter below. Check the tool for its available options and instructions.
Conception Date Calculator
Use our Conception Date Calculator to estimate conception date, due date, ovulation day, fertile window, and pregnancy progress from due date or LMP.
Hair Growth Calculator
Use our Hair Growth Calculator to estimate hair growth, final hair length, or time needed to reach a hair length goal using average growth rates.
t-test Calculator
Use our T-Test Calculator to compute t statistic, p-value, confidence interval, and conclusion for one-sample, Welch, pooled, or paired t-tests.
FFMI Calculator (Fat-Free Mass Index)
Use the FFMI Calculator to estimate fat-free mass index. Review inputs, results, limitations, safety guidance, and FAQs.
Pixels to Inches converter
Pixels to Inches Converter helps you quickly convert px to inches using PPI or DPI. Get accurate results for print, design, and screen sizing.
t-statistic Calculator
Use our t-Statistic Calculator to compute the t value, degrees of freedom, and standard error for one-sample, two-sample, Welch, pooled, or paired t-tests.
Price Elasticity of Demand Calculator
Use this price elasticity of demand calculator to calculate percentage changes, elasticity coefficient, and basic elasticity classification. Review inputs, fo
Mean Median Mode Calculator
Use our Mean Median Mode Calculator to find the average, median, and mode from any data set. Supports raw numbers, value:count input, and sorted preview.
BMI Calculator (Body Mass Index)
Use the BMI Calculator to estimate adult body mass index. Review inputs, results, limitations, safety guidance, and FAQs.
Credit Card Interest Calculator
Estimate credit card interest, payoff time, and total repayment cost using balance, APR, payment amount, and compounding assumptions.
Basis Point (BPS) Calculator
Use this basis point (bps) calculator to calculate rate difference in basis points, percentage points, and decimal form. Review inputs, formulas, examples, li
Wallpaper Calculator
Estimate wallpaper strips and full rolls using wall height, perimeter, roll size, trimming and pattern repeat.
Gravitational Force Calculator
Use our Gravitational Force Calculator to find the force between two masses with Newton’s law of gravitation. Get results in newtons, lbf, and acceleration on each mass.
Child BMI Calculator
Calculate BMI and estimate BMI-for-age percentile for a child or teen, with guidance on measurement and interpretation.
Body Fat Calculator
Use the Body Fat Calculator to estimate body-fat percentage. Review inputs, results, limitations, safety guidance, and FAQs.
Elevation Grade Calculator
Use our Elevation Grade Calculator to find slope ratio, percent grade, angle of elevation, and 1 in N ratio from rise and run with mixed-unit support.
Walking Calorie Calculator
Use this walking calorie calculator to estimate estimated calories used during a walk. Learn the inputs, formulas, examples, limitations, training tips, and F
Chi-Square Calculator
Use our Chi-Square Calculator to run goodness-of-fit and independence tests, or find right-tail p-values and critical χ² values from df and alpha.
Baby Growth Percentile Calculator
Estimate an infant growth percentile for weight, length or head circumference and learn how to interpret the trend.
Plant Spacing Calculator
Use our Plant Spacing Calculator to estimate how many plants fit in a garden bed, crop row, or square-foot layout from area and spacing.
Waist-to-Hip Ratio (WHR) Calculator
Use the Waist-to-Hip Ratio Calculator to estimate waist-to-hip ratio. Review inputs, results, limitations, safety guidance, and FAQs.
Drive Time Calculator
Use our Drive Time Calculator to estimate trip time, arrival time, fuel used, fuel cost, and cost per person from distance, speed, and fuel inputs.
Interest Rate Calculator
Solve for interest rate, principal, balance, or time while distinguishing simple, compound, nominal, and effective rate assumptions.
Dog Age Calculator
Estimate a dog’s human-age equivalent and life stage using age and size, while understanding why the old seven-year rule is limited.
Framing Calculator
Free wall framing calculator: enter wall length/height, stud spacing (16″/24″ o.c.) & openings to get studs, plates, headers, sheathing and cost. Metric/imperial with waste %, steps & PDF.
Grams to Cups Converter
Convert grams to cups by ingredient. Learn why density and packing matter, follow the formula and example, and get practical baking tips plus six FAQs.
Sales Tax Calculator
Use this sales tax calculator to calculate sales tax amount, pre-tax subtotal, and final total. Review inputs, formulas, examples, limitations, and FAQs.
Ideal Gas Law Calculator
Use our Ideal Gas Law Calculator to solve pressure, volume, moles, or temperature with PV = nRT. Supports SI and L·atm gas constants with unit conversion.
Standard Deviation Calculator
Use our Standard Deviation Calculator to find sample or population standard deviation from a data set. Get variance, mean, range, and sorted values fast.
Child Height Percentile Calculator
Use the Child Height Percentile Calculator to estimate a child height percentile. Review inputs, results, limitations, safety guidance, and FAQs.
Cycling Calorie Calculator
Estimate calories burned while cycling from body weight, duration, pace and ride conditions, with guidance for interpreting MET-based results.
Nm to ft-lbs Converter
Use our Nm to ft-lbs Converter to convert newton-meters, foot-pounds, inch-pounds, kgf·cm, kgf·m, and other torque units.
USA Annual Income Calculator
Use this usa annual income calculator to calculate gross annual income and equivalent pay-period amounts. Review inputs, formulas, examples, limitations, and
Break-Even Calculator
Use this break-even calculator to calculate break-even units, break-even revenue. Review key inputs, formulas, scenarios, limitations, and FAQs.
Free Fall Calculator
Use our Free Fall Calculator to find time, distance, final velocity, and average speed from height or time with gravity presets and unit conversion.
Emergency Fund Calculator
Use this emergency fund calculator to calculate recommended reserve target, current shortfall. Review key inputs, formulas, scenarios, limitations, and FAQs.
Calorie Calculator
Use the Calorie Calculator to estimate daily calorie needs. Review inputs, results, limitations, safety guidance, and FAQs.
Benadryl Dosage Calculator for Dogs
A safety-first calculator for vet-approved diphenhydramine arithmetic, with checks for dog weight, product ingredients, interactions, and urgent warning signs.
Data Unit Converter
Convert bits and bytes across decimal and binary storage units while seeing the exact factor used for every result.
Fence Calculator
Estimate fence panels, posts and rails from route length, gates, section spacing and closed-perimeter conditions.
Refinance Calculator
Use this refinance calculator to calculate estimated payment change, interest difference. Review key inputs, formulas, scenarios, limitations, and FAQs.
Stock Calculator
Use this stock calculator to calculate cost basis, proceeds, gain or loss, and percentage return. Review inputs, formulas, examples, limitations, and FAQs.
Significant Figures Calculator
Use our Significant Figures Calculator to count sig figs, round numbers or expressions, and show decimal, scientific, and E notation.
Max Heart Rate Calculator
Use this max heart rate calculator to estimate estimated maximum heart rate in beats per minute. Learn the inputs, formulas, examples, limitations, training t
Bench Press 1RM Calculator
Use this bench press 1rm calculator to estimate estimated one-repetition maximum and optional training percentages. Learn the inputs, formulas, examples, limi
Dose Calculator
Check dose arithmetic from an already verified prescription or label, including mg/kg, total mg and liquid volume conversions.
Final Grade Calculator
Find the final exam score needed to reach a target grade or estimate the course result from an expected exam score.
Savings Goal Calculator
Use this savings goal calculator to calculate required periodic saving, projected growth. Review key inputs, formulas, scenarios, limitations, and FAQs.
Percentage Calculator
Percentage calculator for percent of a number, what percent one value is of another, and finding the whole from a percent.
Percent Yield Calculator
Use our Percent Yield Calculator to calculate chemistry percent yield from actual yield and theoretical yield in mg, g, or kg.
Harris-Benedict Calculator (Basal Metabolic Rate)
Use the Harris-Benedict Calculator to estimate basal metabolic rate. Review inputs, results, limitations, safety guidance, and FAQs.
pH Calculator
Free pH calculator that syncs [H+], [OH−], pOH, concentration, and mass/volume. Supports strong/weak acids and bases, unit options, steps, and PDF.
Dividend Calculator
Use this dividend calculator to calculate periodic and annual dividend income, yield, and projected reinvestment growth. Review inputs, formulas, examples, li
Grams To Calories Calculator
Estimate calories from grams of carbohydrate, protein, fat, or alcohol. Review energy factors, examples, label limitations, and six practical FAQs.
Blood Pressure Category Calculator
Classify an adult blood pressure reading and calculate pulse pressure and estimated mean arterial pressure, with measurement guidance.