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.
Protein Calculator
Estimate a daily protein range from body weight, activity and goal for general nutrition planning.
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.
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.
CAGR (Compound Annual Growth Rate) Calculator
Use this cagr (compound annual growth rate) calculator to calculate compound annual growth rate and annualized growth factor. Review inputs, formulas, example
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.
Half-Life Calculator
Calculate remaining quantity, elapsed time, half-life, decay constant, or mean lifetime with formulas, steps, units, and a worked example.
Image Cropper
Crop JPG, PNG and WebP images with free or fixed ratios, exact dimensions, rotation, flipping and export controls.
Ramp Calculator
Use our Ramp Calculator to find ramp slope angle, grade percent, run, and ramp length from rise, ratio, or accessibility ramp presets.
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
Running Calorie Calculator
Use this running calorie calculator to estimate estimated calories used during a run. Learn the inputs, formulas, examples, limitations, training tips, and FA
Savings Goal Calculator
Use this savings goal calculator to calculate required periodic saving, projected growth. Review key inputs, formulas, scenarios, limitations, and FAQs.
p-value Calculator
Use our P-value Calculator to calculate one-tailed or two-tailed p-values for Z, t, chi-square, and F test statistics.
Lean Body Mass Calculator
Use the Lean Body Mass Calculator to estimate lean body mass. 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.
Salary to Hourly Calculator
Use this salary to hourly calculator to calculate equivalent monthly, weekly, daily, and hourly gross pay. Review inputs, formulas, examples, limitations, and
Winning Percentage Calculator
Use this winning percentage calculator to estimate winning percentage, total games, and record comparisons. Learn the inputs, formulas, examples, limitations,
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.
Baby Growth Percentile Calculator
Estimate an infant growth percentile for weight, length or head circumference and learn how to interpret the trend.
Mortgage Calculator
Use this mortgage calculator to calculate estimated principal-and-interest payment, total interest. Review key inputs, formulas, scenarios, limitations,.
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.
Velocity Calculator
Calculate average velocity, displacement, or elapsed time with unit conversion and clear guidance about direction and the difference between speed and velocity.
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
Desk Height Calculator
Use our Desk Height Calculator to estimate ergonomic chair height, desk height, and monitor height for sitting or standing work.
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.
Probability Calculator
Calculate event probabilities, complements, unions and intersections while checking independence assumptions.
Fraction to Percentage Calculator
Convert fractions to percentages and percentages to simplified fractions. Enter numerator, denominator, or percent to get quick live results.
Pace Calculator
Use this pace calculator to estimate pace per mile or kilometer, average speed, and projected times. Learn the inputs, formulas, examples, limitations, traini
Loan Comparison Calculator
Use this loan comparison calculator to calculate monthly payment, total interest. Review key inputs, formulas, scenarios, limitations, and FAQs.
Ratio Calculator
Simplify, scale and compare ratios or divide a quantity into proportional parts.
Mortgage Interest Calculator
Use this mortgage interest calculator to calculate estimated interest by period, total interest. Review key inputs, formulas, scenarios, limitations, and.
FFMI Calculator (Fat-Free Mass Index)
Use the FFMI Calculator to estimate fat-free mass index. Review inputs, results, limitations, safety guidance, and FAQs.
Target Heart Rate Calculator
Use this target heart rate calculator to estimate estimated lower and upper target heart rates. Learn the inputs, formulas, examples, limitations, training ti
Fraction to Decimal Calculator
Convert a fraction to terminating or repeating decimal form and understand when rounding is required.
Percentage Calculator
Percentage calculator for percent of a number, what percent one value is of another, and finding the whole from a percent.
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.
RPM Calculator
Use our RPM Calculator to find engine RPM from speed or vehicle speed from RPM using overall gear ratio and tire diameter, plus wheel RPM and tire circumference.
Calorie Calculator
Use the Calorie Calculator to estimate daily calorie needs. Review inputs, results, limitations, safety guidance, and FAQs.
Projectile Motion Calculator
Use our Projectile Motion Calculator to find time of flight, range, maximum height, time to peak, and velocity components from speed, angle, height, and gravity.
Dose Calculator
Check dose arithmetic from an already verified prescription or label, including mg/kg, total mg and liquid volume conversions.
Proportion Calculator
Solve a missing value in equivalent ratios and verify the result using equal cross products.
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
Wavelength → Energy Calculator
Use our Wavelength to Energy Calculator to find photon energy from wavelength in joules, eV, and kJ/mol using E = hc / λ with vacuum or custom wave speed.
Long Division Calculator
Perform long division with a quotient, remainder and step-by-step divide-multiply-subtract work.
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.
Weighted Grade Calculator
Calculate a weighted course grade from category percentages and weights, including the normalized grade so far and remaining weight.
Brick Calculator
Estimate brick quantity from net wall area, the brick face, mortar joint, openings and practical waste.
Semester Grade Calculator
Calculate a credit-weighted semester grade from course percentages and credits, then compare the result with an optional target.
Fuel Cost Calculator
Fuel Cost Calculator to estimate fuel used and total trip expense from distance, fuel efficiency, and fuel price.
Circle Skirt Calculator
Circle Skirt Calculator to find waist radius, hem measurements, and fabric requirements for full, half, or quarter skirts.
Air Conditioner Size Calculator
Estimate a room air conditioner’s preliminary BTU and tonnage range from dimensions and major load factors.
CPM Calculator
Use this cpm calculator to calculate cost per thousand impressions, implied cost, or required impressions. Review inputs, formulas, examples, limitations, and
Ohm’s Law Resistance Calculator
Use our Ohm’s Law Resistance Calculator to find resistance from voltage and current. Get instant results in Ω, kΩ, or MΩ plus power and conductance.
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.
GCF Calculator
Find the greatest common factor of integers using factor lists, prime factorization or Euclid’s algorithm.
GPA calculator
Calculate semester GPA and estimate cumulative GPA from course grade points and credit hours, with clear formulas and policy guidance.
Work and Power Calculator
Calculate mechanical work and average power from force, displacement, angle, and elapsed time, with clear joule and watt interpretation.
Compound Interest Calculator
Use this compound interest calculator to calculate future balance, total contributions, and compound growth. Review inputs, formulas, examples, limitations, a
Dog Size & Adult Weight Calculator
Use our Dog Size & Adult Weight Calculator to estimate your puppy’s adult weight from age and current weight. Quick size prediction with pet category output.
Image Compressor
Compress JPG, PNG, WebP, and SVG images in your browser. Choose JPEG or WebP output, adjust quality, resize dimensions, and download.
INR Calculator
Use our INR Calculator to solve for INR, patient PT, control PT, or ISI with the standard PT/INR formula. Fast educational estimate online.
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.
Credit Card Payoff Calculator
Use this credit card payoff calculator to calculate estimated payoff date, number of payments. Review key inputs, formulas, scenarios, limitations, and FAQs.
Surface Area Calculator
Find lateral or total surface area for common three-dimensional solids in square units.
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.
Percentage of a Percentage Calculator
Percentage of a percentage calculator to find cumulative percentage and final value from two related percentage changes.
Rent vs Buy Calculator
Use this rent vs buy calculator to calculate estimated cumulative renting cost, ownership cost. Review key inputs, formulas, scenarios, limitations, and FAQs.
Avogadro’s number calculator
Convert between moles and representative particles using the exact Avogadro constant, with examples for atoms, molecules, ions, and formula units.
Weight Gain Calculator
Use the Weight Gain Calculator to estimate a calorie surplus for weight gain. Review inputs, results, limitations, safety guidance, and FAQs.
Z-score Calculator
Use our Z-Score Calculator to standardize a value or sample mean, convert percentile to z, convert z to percentile, and view left-tail and right-tail probabilities.
Waist-to-Height Ratio (WHtR) Calculator
Use the Waist-to-Height Ratio Calculator to estimate waist-to-height ratio. Review inputs, results, limitations, safety guidance, and FAQs.
Free JPG to PNG Converter
Convert JPG images to PNG format with the embedded converter on this page.
Balance Transfer Calculator
Compare a balance transfer’s fee, promotional period, payment plan, and post-promotion APR against keeping the current credit-card balance.
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.
Cycling Calorie Calculator
Estimate calories burned while cycling from body weight, duration, pace and ride conditions, with guidance for interpreting MET-based results.
Weight Price Comparison Calculator
Use our Weight Price Comparison Calculator to compare two products by price per gram, kilogram, pound, or ounce and find the better value.
Force Calculator
Use our Force Calculator to find force from mass and acceleration with F = ma. Get instant results in newtons, kilonewtons, and pounds-force.
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.
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.
Room Size Calculator
Calculate a rectangular room’s floor, ceiling, wall area, perimeter and volume from inside dimensions.
PPM to Molarity Calculator
PPM to Molarity Calculator to convert parts per million into molarity using molar mass and solution assumptions.
Amortization Calculator
Use this mortgage loan amortization calculator to calculate scheduled payment, principal and interest split. Review key inputs, formulas, scenarios,.
Inflation Calculator
Compare purchasing power between years using a selected price index and understand cumulative inflation, base periods, regional scope, and data revisions.
Decimal to Fraction Calculator
Convert terminating or repeating decimals to reduced fractions and mixed-number form.
Potential Energy Calculator
Calculate near-Earth gravitational potential energy from mass, gravitational acceleration, and height relative to a chosen reference level.
Margin Calculator
Use this margin calculator to calculate gross profit, margin percentage, markup percentage, and missing price variable. Review inputs, formulas, examples, lim
Ideal Weight Calculator
Use the Ideal Weight Calculator to estimate formula-based ideal body weight. Review inputs, results, limitations, safety guidance, and FAQs.
Free HEIC Converter
Use the HEIC converter below. Check the tool for available conversion options and follow its on-screen guidance.
Teen BMI calculator
Use the Teen BMI calculator to estimate a teen BMI percentile. Review inputs, results, limitations, safety guidance, and FAQs.
Car Finance Calculator
Use this car finance calculator to calculate amount financed, monthly payment, total interest, and total loan cost. Review inputs, formulas, examples, limitat
Calorie Deficit Calculator
Use our Calorie Deficit Calculator to estimate BMR, maintenance calories, TDEE, calorie deficit, target calories, and weekly weight-change estimate.
Hiking Calorie Calculator
Estimate calories burned on a hike using weight, moving time, distance, elevation, terrain and backpack load.
Tile Calculator
Estimate tiles, edge cuts and full boxes using the project size, tile dimensions, grout gap and waste allowance.
Cholesterol Ratio Calculator
Use the Cholesterol Ratio Calculator to estimate cholesterol ratios. Review inputs, results, limitations, safety guidance, and FAQs.
Average Percentage Calculator
Average percentage calculator to find simple or weighted averages of multiple percentages with quick, accurate results.
Korean Age Calculator
Korean Age Calculator helps you convert your age using the traditional Korean age system quickly and clearly.
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
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.
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.
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,.
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.