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.
Circle Skirt Calculator
Circle Skirt Calculator to find waist radius, hem measurements, and fabric requirements for full, half, or quarter skirts.
Final Grade Calculator
Find the final exam score needed to reach a target grade or estimate the course result from an expected exam score.
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
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.
Beam Deflection Calculator
Estimate elastic beam deflection for common cantilever and simply supported cases using span, load, elastic modulus, and second moment of area.
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.
Atom Calculator
Use our Atom Calculator to find protons, neutrons, electrons, atomic number, mass number, and ionic charge quickly from standard atomic relationships.
Lease Calculator
Use this lease calculator to calculate estimated monthly lease payment, depreciation charge. Review key inputs, formulas, scenarios, limitations, and FAQs.
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,
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.
Inches to Fraction Calculator
Inches to Fraction Calculator converts decimal inch values into usable fractions for construction, woodworking, machining, and daily measurements.
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.
Korean Age Calculator
Korean Age Calculator helps you convert your age using the traditional Korean age system quickly and clearly.
Body Fat Calculator
Use the Body Fat Calculator to estimate body-fat percentage. Review inputs, results, limitations, safety guidance, and FAQs.
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.
Drywall Calculator
Estimate whole drywall sheets for walls and an optional ceiling using room dimensions, panel size and waste.
Quadratic Formula Calculator
Solve a quadratic equation from coefficients a, b and c and interpret its discriminant and roots.
Decimal to Fraction Calculator
Convert terminating or repeating decimals to reduced fractions and mixed-number form.
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.
Margin Calculator
Use this margin calculator to calculate gross profit, margin percentage, markup percentage, and missing price variable. Review inputs, formulas, examples, lim
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
Balance Transfer Calculator
Compare a balance transfer’s fee, promotional period, payment plan, and post-promotion APR against keeping the current credit-card balance.
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.
Work and Power Calculator
Calculate mechanical work and average power from force, displacement, angle, and elapsed time, with clear joule and watt interpretation.
Ratio Calculator
Simplify, scale and compare ratios or divide a quantity into proportional parts.
GPA calculator
Calculate semester GPA and estimate cumulative GPA from course grade points and credit hours, with clear formulas and policy guidance.
Gas cost calculator
Gas Cost Calculator to estimate gasoline needed, trip fuel spend, and total driving cost by distance, mpg, and gas price.
Avogadro’s number calculator
Convert between moles and representative particles using the exact Avogadro constant, with examples for atoms, molecules, ions, and formula units.
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.
Net Worth Calculator
Use this net worth calculator to calculate total assets, total liabilities. Review key inputs, formulas, scenarios, limitations, and FAQs.
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
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.
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.
Rounding Calculator
Round numbers to a selected place or significant figures and distinguish common rounding methods.
ABSI (A Body Shape Index) Calculator
Use the ABSI Calculator to estimate A Body Shape Index. Review inputs, results, limitations, safety guidance, and FAQs.
Body Shape Calculator
Body Shape Calculator helps you identify your body type from key measurements and understand which shape category fits you best.
Retirement Calculator
Estimate retirement savings, contribution growth, inflation-adjusted value, income target, and potential gap with formulas and planning scenarios.
Sand Calculator
Use our Sand Calculator to estimate sand area, volume, weight, and optional total cost from length, width, depth, density, and price.
Winning Percentage Calculator
Use this winning percentage calculator to estimate winning percentage, total games, and record comparisons. Learn the inputs, formulas, examples, limitations,
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.
APY Calculator
Use this apy calculator to calculate effective annual percentage yield and one-year growth factor. Review inputs, formulas, examples, limitations, and FAQs.
Fraction Calculator
Calculate fraction operations, simplify the result and understand common denominators and reciprocals.
Add Time Calculator
Use our Add Time Calculator to add hours, minutes, seconds, days, weeks, months, and years, then convert the total into your preferred time format.
Potential Energy Calculator
Calculate near-Earth gravitational potential energy from mass, gravitational acceleration, and height relative to a chosen reference level.
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.
Amortization Calculator
Use this mortgage loan amortization calculator to calculate scheduled payment, principal and interest split. Review key inputs, formulas, scenarios,.
AGE CALCULATOR
Age Calculator helps you find exact age in years, months, and days from your date of birth instantly.
Student Loan Calculator
Use this student loan calculator to calculate estimated payment, payoff time. Review key inputs, formulas, scenarios, limitations, and FAQs.
Mortgage Calculator
Use this mortgage calculator to calculate estimated principal-and-interest payment, total interest. Review key inputs, formulas, scenarios, limitations,.
Emergency Fund Calculator
Use this emergency fund calculator to calculate recommended reserve target, current shortfall. Review key inputs, formulas, scenarios, limitations, and FAQs.
Circumference Calculator
Use our Circumference Calculator to find circle radius, diameter, circumference, and area from any one known value with unit conversions.
Area Calculator
Calculate the area of common two-dimensional shapes using dimensions in compatible units.
Macro Calculator
Estimate daily calories and divide them into protein, carbohydrate and fat targets for general planning.
Molarity Calculator
Use our Molarity Calculator to find moles, mass concentration, and molarity from solute mass, molar mass, and solution volume.
Average Percentage Calculator
Average percentage calculator to find simple or weighted averages of multiple percentages with quick, accurate results.
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.
Baby Growth Percentile Calculator
Estimate an infant growth percentile for weight, length or head circumference and learn how to interpret the trend.
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.
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.
Cycling Calorie Calculator
Estimate calories burned while cycling from body weight, duration, pace and ride conditions, with guidance for interpreting MET-based results.
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.
Plastic Footprint Calculator
Estimate annual household plastic use in kilograms and pounds from common disposable items, frequencies and model item weights.
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.
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
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.
Marks Percentage Calculator
Calculate percentage from obtained and total marks, see marks lost, and compare your score with an optional passing or target percentage.
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.
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.
Image Converter Pro
Convert images among supported formats while managing quality, transparency, dimensions, metadata, file size, and browser compatibility.
Credit Card Interest Calculator
Estimate credit card interest, payoff time, and total repayment cost using balance, APR, payment amount, and compounding assumptions.
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.
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.
Room Size Calculator
Calculate a rectangular room’s floor, ceiling, wall area, perimeter and volume from inside dimensions.
Simple Loan Calculator
Use this simple loan calculator to calculate simple interest, total repayment, and periodic payment. Review inputs, formulas, examples, limitations, and FAQs.
Personal Loan Calculator
Use this personal loan calculator to calculate estimated payment, total interest. Review key inputs, formulas, scenarios, limitations, and FAQs.
BMR — Basal Metabolic Rate (Mifflin–St Jeor)
Use the BMR to estimate basal metabolic rate. Review inputs, results, limitations, safety guidance, and FAQs.
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.
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.
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.
Volume Calculator
Calculate the volume of common three-dimensional solids using measurements in compatible units.
Semester Grade Calculator
Calculate a credit-weighted semester grade from course percentages and credits, then compare the result with an optional target.
Weighted Grade Calculator
Calculate a weighted course grade from category percentages and weights, including the normalized grade so far and remaining weight.
Cholesterol Ratio Calculator
Use the Cholesterol Ratio Calculator to estimate cholesterol ratios. Review inputs, results, limitations, safety guidance, and FAQs.
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.
Child BMI Calculator
Calculate BMI and estimate BMI-for-age percentile for a child or teen, with guidance on measurement and interpretation.
Percentage to CGPA Calculator
Convert percentage to CGPA using proportional, legacy 9.5, or custom institutional methods, with scale checks and policy guidance.
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.
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.
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
Budget Calculator
Use this budget calculator to calculate monthly surplus or deficit, category totals. Review key inputs, formulas, scenarios, limitations, and FAQs.
Image Color Picker
Pick an exact pixel from an uploaded image and copy its color in HEX, RGB, HSL, HSV, CMYK or OKLCH formats.
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.
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
Compound Interest Calculator
Use this compound interest calculator to calculate future balance, total contributions, and compound growth. Review inputs, formulas, examples, limitations, a
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.
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.
Fence Calculator
Estimate fence panels, posts and rails from route length, gates, section spacing and closed-perimeter conditions.
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.
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.