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.
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.
Document + PDF Converter
Convert supported documents to or from PDF while checking layout fidelity, fonts, page order, privacy, file limits, and output compatibility.
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.
Asphalt Calculator
Estimate compacted asphalt volume and tonnage from paving area, thickness, density and ordering allowance.
Gas cost calculator
Gas Cost Calculator to estimate gasoline needed, trip fuel spend, and total driving cost by distance, mpg, and gas price.
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,.
Circle Skirt Calculator
Circle Skirt Calculator to find waist radius, hem measurements, and fabric requirements for full, half, or quarter skirts.
Personal Loan Calculator
Use this personal loan calculator to calculate estimated payment, total interest. Review key inputs, formulas, scenarios, limitations, and FAQs.
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.
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
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
Heart Age Calculator
Compare an educational cardiovascular risk profile with a reference age and understand the factors influencing the estimate.
VAT Calculator
Use this vat calculator to calculate tax amount, price before tax, and price including tax. 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.
Room Size Calculator
Calculate a rectangular room’s floor, ceiling, wall area, perimeter and volume from inside dimensions.
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.
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
PPM to Molarity Calculator
PPM to Molarity Calculator to convert parts per million into molarity using molar mass and solution assumptions.
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
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
Blood Pressure Category Calculator
Classify an adult blood pressure reading and calculate pulse pressure and estimated mean arterial pressure, with measurement guidance.
Percentage of a Percentage Calculator
Percentage of a percentage calculator to find cumulative percentage and final value from two related percentage changes.
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.
Fence Calculator
Estimate fence panels, posts and rails from route length, gates, section spacing and closed-perimeter conditions.
Surface Area Calculator
Find lateral or total surface area for common three-dimensional solids in square units.
Protein Calculator
Estimate a daily protein range from body weight, activity and goal for general nutrition planning.
Period Calculator
Predict your next period start/end, ovulation day, and fertile window from LMP and cycle length with this free period calculator.
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.
Simple Loan Calculator
Use this simple loan calculator to calculate simple interest, total repayment, and periodic payment. Review inputs, formulas, examples, limitations, and FAQs.
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.
Final Grade Calculator
Find the final exam score needed to reach a target grade or estimate the course result from an expected exam score.
Gravel Calculator
Use our Gravel Calculator to estimate gravel volume, weight, tons, cubic yards, coverage, and total cost from area, depth, density, and price.
Net Worth Calculator
Use this net worth calculator to calculate total assets, total liabilities. Review key inputs, formulas, scenarios, limitations, and FAQs.
Salary calculator
Convert gross salary among annual, monthly, weekly, daily, and hourly amounts using your actual work schedule and paid-time assumptions.
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.
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.
Prime Factorization Calculator
Break a positive integer into its unique product of prime powers and review factor-tree logic.
Break-Even Calculator
Use this break-even calculator to calculate break-even units, break-even revenue. Review key inputs, formulas, scenarios, limitations, and FAQs.
mcg to IU Converter
Convert between micrograms and international units using the correct vitamin and chemical form, with label-reading and safety guidance.
Mortgage Calculator
Use this mortgage calculator to calculate estimated principal-and-interest payment, total interest. Review key inputs, formulas, scenarios, limitations,.
Dose Calculator
Check dose arithmetic from an already verified prescription or label, including mg/kg, total mg and liquid volume conversions.
mg to mL Calculator
Use our mg to mL Calculator to convert weight and volume using liquid density, preset liquids, or medication concentration in mg/mL or mg/5 mL.
Velocity Calculator
Calculate average velocity, displacement, or elapsed time with unit conversion and clear guidance about direction and the difference between speed and velocity.
Child Height Percentile Calculator
Use the Child Height Percentile Calculator to estimate a child height percentile. Review inputs, results, limitations, safety guidance, and FAQs.
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.
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.
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.
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.
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.
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.
Fraction Calculator
Calculate fraction operations, simplify the result and understand common denominators and reciprocals.
Volume Calculator
Calculate the volume of common three-dimensional solids using measurements in compatible units.
Refinance Calculator
Use this refinance calculator to calculate estimated payment change, interest difference. Review key inputs, formulas, scenarios, limitations, and FAQs.
Percentage Decrease Calculator
Percentage decrease calculator to find the drop between two values or solve the missing initial, final, or decrease percentage fast.
Weighted Grade Calculator
Calculate a weighted course grade from category percentages and weights, including the normalized grade so far and remaining weight.
WebP Converter
Convert JPG, PNG, WebP, or SVG images to WebP in your browser. Adjust quality, resize by max width or height, preview, and download.
Margin of Error Calculator
Use our Margin of Error Calculator to find margin of error for a mean or proportion from sample size, confidence level, and z value.
Steps to Miles Calculator
Use this steps to miles calculator to estimate estimated distance in miles and kilometers. Learn the inputs, formulas, examples, limitations, training tips, a
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.
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.
mmol/L to mg/dL Calculator
Use the mmol/L to mg/dL Calculator to estimate glucose unit conversions. Review inputs, results, limitations, safety guidance, and FAQs.
Desk Height Calculator
Use our Desk Height Calculator to estimate ergonomic chair height, desk height, and monitor height for sitting or standing work.
Hiking Calorie Calculator
Estimate calories burned on a hike using weight, moving time, distance, elevation, terrain and backpack load.
Lease Calculator
Use this lease calculator to calculate estimated monthly lease payment, depreciation charge. 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.
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.
Favicon Generator
Turn one logo or image into ICO, PNG and app-icon files with crop, padding, mask and background controls.
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.
Image Color Picker
Pick an exact pixel from an uploaded image and copy its color in HEX, RGB, HSL, HSV, CMYK or OKLCH formats.
PayPal Fee Calculator
Estimate transaction fees, net receipts, or a gross request amount using the current percentage and fixed fee for your transaction type.
Cholesterol Units Converter
Convert cholesterol and triglyceride measurements between mg/dL and mmol/L with analyte-specific factors and careful result interpretation.
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.
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.
Potential Energy Calculator
Calculate near-Earth gravitational potential energy from mass, gravitational acceleration, and height relative to a chosen reference level.
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.
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.
Scientific Calculator
Evaluate scientific expressions involving powers, roots, logarithms, constants and trigonometric functions.
Dilution Ratio Calculator
Use our Dilution Ratio Calculator to calculate concentrate, water, final volume, or dilution ratio for water-to-concentrate mixes.
Balance Transfer Calculator
Compare a balance transfer’s fee, promotional period, payment plan, and post-promotion APR against keeping the current credit-card balance.
Kinetic Energy Calculator
Calculate translational kinetic energy from mass and velocity, rearrange the formula, convert units, and explore the squared effect of speed.
Inches to Fraction Calculator
Inches to Fraction Calculator converts decimal inch values into usable fractions for construction, woodworking, machining, and daily measurements.
Drywall Calculator
Estimate whole drywall sheets for walls and an optional ceiling using room dimensions, panel size and waste.
Grams To Ounces Calculator
Use our Grams to Ounces Calculator to convert grams to ounces, ounces to grams, kilograms, milligrams, and troy ounces.
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.
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.
Triangle Calculator
Solve a triangle’s missing sides, angles, area and perimeter from sufficient known measurements.
Pre & Post-Money Valuation Calculator
Use this pre & post-money valuation calculator to calculate post-money valuation and implied investor or founder ownership. Review inputs, formulas, examples,
Time Calculator
Time Calculator helps you add, subtract, and measure time differences in hours and minutes with ease.
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.
Reading Time Calculator
Use our Reading Time Calculator to estimate how long it takes to read a book, daily pages read, and time needed to finish from pages and reading speed.
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.
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
CGPA Calculator
Calculate cumulative CGPA from semester GPA and credit hours with a credit-weighted formula, worked example, and policy checks.
Debt Payoff Calculator
Use this debt payoff calculator to calculate estimated payoff date, total interest. Review key inputs, formulas, scenarios, limitations, and FAQs.
Brick Calculator
Estimate brick quantity from net wall area, the brick face, mortar joint, openings and practical waste.
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.
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.
LCM Calculator
Find the least common multiple of integers using prime factors or the relationship between LCM and GCF.
Ramp Calculator
Use our Ramp Calculator to find ramp slope angle, grade percent, run, and ramp length from rise, ratio, or accessibility ramp presets.
Fuel Cost Calculator
Fuel Cost Calculator to estimate fuel used and total trip expense from distance, fuel efficiency, and fuel price.