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
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Free to use
Use free online calculators and converters for everyday questions, quick checks, and practical planning.
Weighted Grade Calculator
Calculate a weighted course grade from category percentages and weights, including the normalized grade so far and remaining weight.
BTU Calculator
Estimate a preliminary room heating or cooling load from volume, temperature difference and major adjustments.
Blood Type Calculator
Use the Blood Type Calculator to estimate possible child blood types. Review inputs, results, limitations, safety guidance, and FAQs.
Air Conditioner Size Calculator
Estimate a room air conditioner’s preliminary BTU and tonnage range from dimensions and major load factors.
Margin Calculator
Use this margin calculator to calculate gross profit, margin percentage, markup percentage, and missing price variable. Review inputs, formulas, examples, lim
Salary calculator
Convert gross salary among annual, monthly, weekly, daily, and hourly amounts using your actual work schedule and paid-time assumptions.
Image Compressor
Compress JPG, PNG, WebP, and SVG images in your browser. Choose JPEG or WebP output, adjust quality, resize dimensions, and download.
Marks Percentage Calculator
Calculate percentage from obtained and total marks, see marks lost, and compare your score with an optional passing or target percentage.
Gas cost calculator
Gas Cost Calculator to estimate gasoline needed, trip fuel spend, and total driving cost by distance, mpg, and gas price.
PAY RAISE CALCULATOR
Use this pay raise calculator to calculate new pay, increase per period, and annualized difference. Review inputs, formulas, examples, limitations, and FAQs.
Free AVIF Image Converter
Easily convert AVIF images to JPG, PNG, or WebP formats with our user-friendly tool. Fast, efficient, and free for all your image conversion needs.
Probability Calculator
Calculate event probabilities, complements, unions and intersections while checking independence assumptions.
Dividend Calculator
Use this dividend calculator to calculate periodic and annual dividend income, yield, and projected reinvestment growth. Review inputs, formulas, examples, li
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
Electricity Cost Calculator
Use our Electricity Cost Calculator to estimate appliance energy use, period cost, and annual electricity cost from watts, usage time, and price per kWh.
Flooring Calculator
Calculate floor area, cutting waste and the number of complete flooring boxes or rolls to purchase.
Teen BMI calculator
Use the Teen BMI calculator to estimate a teen BMI percentile. Review inputs, results, limitations, safety guidance, and FAQs.
Cord of Wood Calculator
Use our Cord of Wood Calculator to estimate firewood stack volume, full cords, face cords, cord percentage, and cost from stack dimensions.
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.
Asphalt Calculator
Estimate compacted asphalt volume and tonnage from paving area, thickness, density and ordering allowance.
Ramp Calculator
Use our Ramp Calculator to find ramp slope angle, grade percent, run, and ramp length from rise, ratio, or accessibility ramp presets.
Grams To Ounces Calculator
Use our Grams to Ounces Calculator to convert grams to ounces, ounces to grams, kilograms, milligrams, and troy ounces.
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.
Grams To Calories Calculator
Estimate calories from grams of carbohydrate, protein, fat, or alcohol. Review energy factors, examples, label limitations, and six practical FAQs.
BMI Calculator (Body Mass Index)
Use the BMI Calculator to estimate adult body mass index. Review inputs, results, limitations, safety guidance, and FAQs.
Dihybrid Cross (Punnett Square) Calculator
Use the Dihybrid Cross Calculator to generate a 4×4 Punnett square, gametes, genotypes, phenotypes, and probabilities for two traits.
Average Percentage Calculator
Average percentage calculator to find simple or weighted averages of multiple percentages with quick, accurate results.
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.
Kinetic Energy Calculator
Calculate translational kinetic energy from mass and velocity, rearrange the formula, convert units, and explore the squared effect of speed.
Water Intake Calculator
Estimate a general daily hydration target from body weight, activity and climate, with practical guidance on interpreting the result.
Refinance Calculator
Use this refinance calculator to calculate estimated payment change, interest difference. Review key inputs, formulas, scenarios, limitations, and FAQs.
Gravel Calculator
Use our Gravel Calculator to estimate gravel volume, weight, tons, cubic yards, coverage, and total cost from area, depth, density, and price.
Credit Card Interest Calculator
Estimate credit card interest, payoff time, and total repayment cost using balance, APR, payment amount, and compounding assumptions.
Percentage Decrease Calculator
Percentage decrease calculator to find the drop between two values or solve the missing initial, final, or decrease percentage fast.
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.
Cholesterol Units Converter
Convert cholesterol and triglyceride measurements between mg/dL and mmol/L with analyte-specific factors and careful result interpretation.
Calories Burned Calculator
Use this calories burned calculator to estimate estimated exercise energy expenditure in calories. Learn the inputs, formulas, examples, limitations, training
PPM to Molarity Calculator
PPM to Molarity Calculator to convert parts per million into molarity using molar mass and solution assumptions.
Roofing Shingle Calculator
Estimate sloped roof area, roofing squares and bundles from footprint, pitch and a complexity allowance.
Number to Million Converter
Number to Million Converter to express large figures in millions instantly for finance, reports, and easy reading.
Fraction to Decimal Calculator
Convert a fraction to terminating or repeating decimal form and understand when rounding is required.
Area Calculator
Calculate the area of common two-dimensional shapes using dimensions in compatible units.
Rounding Calculator
Round numbers to a selected place or significant figures and distinguish common rounding methods.
Document + PDF Converter
Convert supported documents to or from PDF while checking layout fidelity, fonts, page order, privacy, file limits, and output compatibility.
Fuel Cost Calculator
Fuel Cost Calculator to estimate fuel used and total trip expense from distance, fuel efficiency, and fuel price.
IQ PERCENTILE CALCULATOR
Use our IQ Percentile Calculator to convert an IQ score into percentile rank, percent above, and percent below using SD 15 or SD 16 normal-distribution scales.
Velocity Calculator
Calculate average velocity, displacement, or elapsed time with unit conversion and clear guidance about direction and the difference between speed and velocity.
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.
Attendance Percentage Calculator
Calculate current attendance, missed classes, classes needed to reach a target, and how many future classes you may be able to miss.
Bikini Calculator
Use our Bikini Calculator to estimate your body shape from bust, waist, high hip, and hip measurements, then get bikini style suggestions that fit your shape.
Shannon Diversity Index Calculator
Calculate Shannon diversity H′, species richness, total abundance and evenness from species counts using ln, log10 or log2.
Grade Curve Calculator
Estimate a curved score with fixed points, highest-score, class-average, or square-root methods and compare how each rule changes a grade.
Taper Calculator
Use our Taper Calculator to find taper per length, taper ratio, half-angle, and included angle from large diameter, small diameter, and taper length.
Door and Window Area Calculator
Total rectangular door and window opening area and perimeter while distinguishing unit and rough-opening sizes.
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
Percentage Calculator
Percentage calculator for percent of a number, what percent one value is of another, and finding the whole from a percent.
Percent Off Calculator
Use this percent off calculator to calculate discount amount, sale price, and total savings. Review inputs, formulas, examples, limitations, and FAQs.
Paint Calculator
Estimate wall-paint quantity from room dimensions, openings, coats, coverage and a practical allowance.
Insulation Calculator
Estimate net insulation area and packages while checking R-value, cavity and product coverage separately.
Mixed Number Calculator
Calculate with mixed numbers by converting whole-and-fraction parts to improper fractions and simplifying.
Log Calculator (Logarithm)
Log Calculator helps you solve logarithms with base 10, base e, base 2, or any custom base. Get fast and accurate log results online.
Taco Bar Calculator
Plan taco meat, tortillas, fillings, and toppings for any guest count with practical portions, food-safety guidance, examples, and six useful FAQs.
Mortgage Interest Calculator
Use this mortgage interest calculator to calculate estimated interest by period, total interest. Review key inputs, formulas, scenarios, limitations, and.
Dog Pregnancy (Due Date) Calculator
Use the Dog Pregnancy Due Date Calculator to estimate a whelping date and delivery window from mating, ovulation, LH surge, or diestrus.
Balance Transfer Calculator
Compare a balance transfer’s fee, promotional period, payment plan, and post-promotion APR against keeping the current credit-card balance.
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.
Harris-Benedict Calculator (Basal Metabolic Rate)
Use the Harris-Benedict Calculator to estimate basal metabolic rate. Review inputs, results, limitations, safety guidance, and FAQs.
Acceleration Calculator
Calculate average acceleration from initial velocity, final velocity, and elapsed time while keeping direction, signs, and units consistent.
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.
Percentage to CGPA Calculator
Convert percentage to CGPA using proportional, legacy 9.5, or custom institutional methods, with scale checks and policy guidance.
Concrete Calculator
Estimate concrete volume in cubic yards, feet, and meters, plus 40, 60, or 80 lb bags for slabs, pads, and rectangular pours with waste.
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.
Free HEIC Converter
Use the HEIC converter below. Check the tool for available conversion options and follow its on-screen guidance.
Surface Area Calculator
Find lateral or total surface area for common three-dimensional solids in square units.
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.
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.
Margin & VAT Calculator
Use this margin & vat calculator to calculate net selling price, gross profit, tax amount, and final price. Review inputs, formulas, examples, limitations, an
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.
Tile Calculator
Estimate tiles, edge cuts and full boxes using the project size, tile dimensions, grout gap and waste allowance.
Emergency Fund Calculator
Use this emergency fund calculator to calculate recommended reserve target, current shortfall. Review key inputs, formulas, scenarios, limitations, and FAQs.
Body Fat Calculator
Use the Body Fat Calculator to estimate body-fat percentage. Review inputs, results, limitations, safety guidance, and FAQs.
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.
BC to AD Year Difference Calculator
Use our BC to AD Year Difference Calculator to find the years between BC/BCE and AD/CE dates using the no-year-0 formula.
Budget Calculator
Use this budget calculator to calculate monthly surplus or deficit, category totals. Review key inputs, formulas, scenarios, limitations, and FAQs.
Mortgage Calculator with Taxes and Insurance
Use this mortgage calculator with taxes and insurance to calculate estimated total monthly housing payment and component breakdown. Review key inputs,.
Desk Height Calculator
Use our Desk Height Calculator to estimate ergonomic chair height, desk height, and monitor height for sitting or standing work.
Minutes to Hours Converter
Minutes to Hours Converter to instantly convert minutes into decimal hours or hours and minutes with clear results.
Sample Size Calculator
Use our Sample Size Calculator to estimate sample size for a mean or proportion from confidence level, margin of error, and optional finite population correction.
Cycling Calorie Calculator
Estimate calories burned while cycling from body weight, duration, pace and ride conditions, with guidance for interpreting MET-based results.
Inches to Fraction Calculator
Inches to Fraction Calculator converts decimal inch values into usable fractions for construction, woodworking, machining, and daily measurements.
Data Unit Converter
Convert bits and bytes across decimal and binary storage units while seeing the exact factor used for every result.
Retirement Calculator
Estimate retirement savings, contribution growth, inflation-adjusted value, income target, and potential gap with formulas and planning scenarios.
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.
Commission Calculator
Use this commission calculator to calculate commission earned and combined compensation. Review key inputs, formulas, scenarios, limitations, and FAQs.
Blood Pressure Category Calculator
Classify an adult blood pressure reading and calculate pulse pressure and estimated mean arterial pressure, with measurement guidance.
Drywall Calculator
Estimate whole drywall sheets for walls and an optional ceiling using room dimensions, panel size and waste.
Work Calculator
Calculate mechanical work using force, displacement, and the angle between them, with sign conventions, examples, and unit guidance.
Age Difference Calculator
Use our Age Difference Calculator to find the exact age gap between two dates of birth in years, months, days, total months, total days, and approximate years.
Topsoil Calculator
Estimate topsoil volume, bags or mass from the measured area, fill depth and the supplier’s product information.
Molarity Calculator
Use our Molarity Calculator to find moles, mass concentration, and molarity from solute mass, molar mass, and solution volume.