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.
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.
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
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.
Balance Transfer Calculator
Compare a balance transfer’s fee, promotional period, payment plan, and post-promotion APR against keeping the current credit-card balance.
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.
Ohm’s Law Current Calculator
Use our Ohm’s Law Current Calculator to find current from voltage and resistance. Get instant results in A, mA, or µA plus power and conductance.
mcg to IU Converter
Convert between micrograms and international units using the correct vitamin and chemical form, with label-reading and safety guidance.
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.
Acceleration Calculator
Calculate average acceleration from initial velocity, final velocity, and elapsed time while keeping direction, signs, and units consistent.
Lottery Tax Calculator
Use this lottery tax calculator to calculate estimated withholding and after-tax proceeds. Review inputs, formulas, examples, limitations, and FAQs.
Number to Million Converter
Number to Million Converter to express large figures in millions instantly for finance, reports, and easy reading.
Percentage Change Calculator
Use our Percentage Change Calculator to quickly find percent increase or decrease between two values. Instant results, step-by-step breakdown, free & easy to use.
Free JPG to PNG Converter
Convert JPG images to PNG format with the embedded converter on this page.
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.
Weighted Grade Calculator
Calculate a weighted course grade from category percentages and weights, including the normalized grade so far and remaining weight.
CPM Calculator
Use this cpm calculator to calculate cost per thousand impressions, implied cost, or required impressions. Review inputs, formulas, examples, limitations, and
Debt Payoff Calculator
Use this debt payoff calculator to calculate estimated payoff date, total interest. Review key inputs, formulas, scenarios, limitations, and FAQs.
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.
Protein Calculator
Estimate a daily protein range from body weight, activity and goal for general nutrition planning.
Avogadro’s number calculator
Convert between moles and representative particles using the exact Avogadro constant, with examples for atoms, molecules, ions, and formula units.
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
Body Fat Calculator
Use the Body Fat Calculator to estimate body-fat percentage. Review inputs, results, limitations, safety guidance, and FAQs.
Baby Growth Percentile Calculator
Estimate an infant growth percentile for weight, length or head circumference and learn how to interpret the trend.
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.
Favicon Generator
Turn one logo or image into ICO, PNG and app-icon files with crop, padding, mask and background controls.
Area Calculator
Calculate the area of common two-dimensional shapes using dimensions in compatible units.
Room Size Calculator
Calculate a rectangular room’s floor, ceiling, wall area, perimeter and volume from inside dimensions.
Square Root Calculator
Use our Square Root Calculator to find the principal square root of a number or reverse-calculate x from a square root value.
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.
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.
Percent Off Calculator
Use this percent off calculator to calculate discount amount, sale price, and total savings. Review inputs, formulas, examples, limitations, and FAQs.
FFMI Calculator (Fat-Free Mass Index)
Use the FFMI Calculator to estimate fat-free mass index. Review inputs, results, limitations, safety guidance, and FAQs.
Insulation Calculator
Estimate net insulation area and packages while checking R-value, cavity and product coverage separately.
Budget Calculator
Use this budget calculator to calculate monthly surplus or deficit, category totals. Review key inputs, formulas, scenarios, limitations, and FAQs.
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.
Teen BMI calculator
Use the Teen BMI calculator to estimate a teen BMI percentile. Review inputs, results, limitations, safety guidance, and FAQs.
Image Compressor
Compress JPG, PNG, WebP, and SVG images in your browser. Choose JPEG or WebP output, adjust quality, resize dimensions, and download.
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.
Blood Type Calculator
Use the Blood Type Calculator to estimate possible child blood types. Review inputs, results, limitations, safety guidance, and FAQs.
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
All-in-one Home Loan Calculator
Use this all-in-one home loan calculator to calculate estimated payment, cash needed, amortization, affordability indicators, and total loan cost. Review inpu
Document + PDF Converter
Convert supported documents to or from PDF while checking layout fidelity, fonts, page order, privacy, file limits, and output compatibility.
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.
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.
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.
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.
Slope Calculator
Use our Slope Calculator to find slope, angle, percent grade, line equation, y-intercept, rise/run, and distance using two points or other methods.
Child BMI Calculator
Calculate BMI and estimate BMI-for-age percentile for a child or teen, with guidance on measurement and interpretation.
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.
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.
Percentage to CGPA Calculator
Convert percentage to CGPA using proportional, legacy 9.5, or custom institutional methods, with scale checks and policy guidance.
Ramp Calculator
Use our Ramp Calculator to find ramp slope angle, grade percent, run, and ramp length from rise, ratio, or accessibility ramp presets.
Basic Calculator
Perform everyday arithmetic with decimals, signs, parentheses and common percentage operations.
Fraction to Percentage Calculator
Convert fractions to percentages and percentages to simplified fractions. Enter numerator, denominator, or percent to get quick live results.
VAT Calculator
Use this vat calculator to calculate tax amount, price before tax, and price including tax. Review inputs, formulas, examples, limitations, and FAQs.
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.
Gravel Calculator
Use our Gravel Calculator to estimate gravel volume, weight, tons, cubic yards, coverage, and total cost from area, depth, density, and price.
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.
Shannon Diversity Index Calculator
Calculate Shannon diversity H′, species richness, total abundance and evenness from species counts using ln, log10 or log2.
BTU Calculator
Estimate a preliminary room heating or cooling load from volume, temperature difference and major adjustments.
Lease Calculator
Use this lease calculator to calculate estimated monthly lease payment, depreciation charge. Review key inputs, formulas, scenarios, limitations, and FAQs.
Fraction Calculator
Calculate fraction operations, simplify the result and understand common denominators and reciprocals.
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.
Heart Rate Zone Calculator
Use this heart rate zone calculator to estimate estimated heart-rate training zones in beats per minute. Learn the inputs, formulas, examples, limitations, tr
PPM to Molarity Calculator
PPM to Molarity Calculator to convert parts per million into molarity using molar mass and solution assumptions.
Image Color Picker
Pick an exact pixel from an uploaded image and copy its color in HEX, RGB, HSL, HSV, CMYK or OKLCH formats.
Velocity Calculator
Calculate average velocity, displacement, or elapsed time with unit conversion and clear guidance about direction and the difference between speed and velocity.
Rounding Calculator
Round numbers to a selected place or significant figures and distinguish common rounding methods.
Calorie Deficit Calculator
Use our Calorie Deficit Calculator to estimate BMR, maintenance calories, TDEE, calorie deficit, target calories, and weekly weight-change estimate.
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.
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.
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.
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.
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
Volume Calculator
Calculate the volume of common three-dimensional solids using measurements in compatible units.
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.
Wallpaper Calculator
Estimate wallpaper strips and full rolls using wall height, perimeter, roll size, trimming and pattern repeat.
Hamster Age Calculator
Use our Hamster Age Calculator to convert hamster years to human years or human age back to hamster age with chart-based interpolation.
Weight Gain Calculator
Use the Weight Gain Calculator to estimate a calorie surplus for weight gain. Review inputs, results, limitations, safety guidance, and FAQs.
Adjusted Body Weight Calculator
Use the Adjusted Body Weight Calculator to estimate adjusted body weight. Review inputs, results, limitations, safety guidance, and FAQs.
Ratio Calculator
Simplify, scale and compare ratios or divide a quantity into proportional parts.
Prime Factorization Calculator
Break a positive integer into its unique product of prime powers and review factor-tree logic.
Long Division Calculator
Perform long division with a quotient, remainder and step-by-step divide-multiply-subtract work.
Retirement Calculator
Estimate retirement savings, contribution growth, inflation-adjusted value, income target, and potential gap with formulas and planning scenarios.
IQR (Interquartile Range) Calculator
Use our IQR Calculator(Interquartile Range) to find Q1, Q3, median, and interquartile range from a data set. Supports raw numbers, value:count input, and two quartile methods.
Gas cost calculator
Gas Cost Calculator to estimate gasoline needed, trip fuel spend, and total driving cost by distance, mpg, and gas price.
ROI (Return on Investment) Calculator
Use this roi (return on investment) calculator to calculate net gain, return on investment percentage, and optional annualized comparison. Review inputs, form
Cycling Calorie Calculator
Estimate calories burned while cycling from body weight, duration, pace and ride conditions, with guidance for interpreting MET-based results.
Bird Age Calculator
Use our Bird Age Calculator to convert bird years to human years or human age back to bird age by species or custom lifespan.
Hiking Calorie Calculator
Estimate calories burned on a hike using weight, moving time, distance, elevation, terrain and backpack load.
Dilution Ratio Calculator
Use our Dilution Ratio Calculator to calculate concentrate, water, final volume, or dilution ratio for water-to-concentrate mixes.
Time Calculator
Time Calculator helps you add, subtract, and measure time differences in hours and minutes with ease.
APY Calculator
Use this apy calculator to calculate effective annual percentage yield and one-year growth factor. Review inputs, formulas, examples, limitations, and FAQs.
Harris-Benedict Calculator (Basal Metabolic Rate)
Use the Harris-Benedict Calculator to estimate basal metabolic rate. Review inputs, results, limitations, safety guidance, and FAQs.
Interest Rate Calculator
Solve for interest rate, principal, balance, or time while distinguishing simple, compound, nominal, and effective rate assumptions.
Data Unit Converter
Convert bits and bytes across decimal and binary storage units while seeing the exact factor used for every result.
GPA calculator
Calculate semester GPA and estimate cumulative GPA from course grade points and credit hours, with clear formulas and policy guidance.
Pipe Volume Calculator
Calculate pipe volume from inner diameter and length. Get capacity in m³, liters, and US gallons (plus per-length). Supports mm/in and ft/m. Shows formula and steps; instant results & PDF.
CGPA Calculator
Calculate cumulative CGPA from semester GPA and credit hours with a credit-weighted formula, worked example, and policy checks.