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.
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.
Period Calculator
Predict your next period start/end, ovulation day, and fertile window from LMP and cycle length with this free period calculator.
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.
Surface Area Calculator
Find lateral or total surface area for common three-dimensional solids in square units.
CGPA to Percentage Calculator
Convert CGPA to percentage with proportional, legacy 9.5, or custom institutional methods, plus clear policy guidance and examples.
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
Outlier Calculator (Tukey Fences)
Use our Outlier Calculator to find low and high outliers with Tukey fences and the IQR method. Get Q1, Q3, IQR, fences, counts, and sorted data fast.
Marks Percentage Calculator
Calculate percentage from obtained and total marks, see marks lost, and compare your score with an optional passing or target percentage.
Child Height Percentile Calculator
Use the Child Height Percentile Calculator to estimate a child height percentile. 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.
Triangle Calculator
Solve a triangle’s missing sides, angles, area and perimeter from sufficient known measurements.
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.
Decking Calculator
Estimate deck-board rows, pieces and linear length using actual board dimensions, spacing, direction and waste.
Volume Calculator
Calculate the volume of common three-dimensional solids using measurements in compatible units.
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.
Time Calculator
Time Calculator helps you add, subtract, and measure time differences in hours and minutes with ease.
VAT Calculator
Use this vat calculator to calculate tax amount, price before tax, and price including tax. Review inputs, formulas, examples, limitations, and FAQs.
Hiking Calorie Calculator
Estimate calories burned on a hike using weight, moving time, distance, elevation, terrain and backpack load.
Blood Pressure Category Calculator
Classify an adult blood pressure reading and calculate pulse pressure and estimated mean arterial pressure, with measurement guidance.
Prime Factorization Calculator
Break a positive integer into its unique product of prime powers and review factor-tree logic.
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
Velocity Calculator
Calculate average velocity, displacement, or elapsed time with unit conversion and clear guidance about direction and the difference between speed and velocity.
Square Footage Calculator
Square Footage Calculator helps you measure room area, total square feet, and material cost quickly with accurate results.
Minutes to Hours Converter
Minutes to Hours Converter to instantly convert minutes into decimal hours or hours and minutes with clear results.
Board Foot Calculator
Calculate board feet from lumber thickness, width, length, and quantity. Learn the formula, compare prices, and estimate waste for a woodworking project.
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.
Percent Off Calculator
Use this percent off calculator to calculate discount amount, sale price, and total savings. Review inputs, formulas, examples, limitations, and FAQs.
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
Fraction to Percentage Calculator
Convert fractions to percentages and percentages to simplified fractions. Enter numerator, denominator, or percent to get quick live results.
Topsoil Calculator
Estimate topsoil volume, bags or mass from the measured area, fill depth and the supplier’s product information.
Grams To Ounces Calculator
Use our Grams to Ounces Calculator to convert grams to ounces, ounces to grams, kilograms, milligrams, and troy ounces.
Credit Card Interest Calculator
Estimate credit card interest, payoff time, and total repayment cost using balance, APR, payment amount, and compounding assumptions.
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
Favicon Generator
Turn one logo or image into ICO, PNG and app-icon files with crop, padding, mask and background controls.
One Rep Max Calculator
Estimate your one-repetition maximum from a completed submaximal set and translate it into practical training percentages.
Compound Interest Calculator
Use this compound interest calculator to calculate future balance, total contributions, and compound growth. Review inputs, formulas, examples, limitations, a
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.
Exponent Calculator
Exponent Calculator helps you solve powers, positive and negative exponents, and exponential values quickly with clear, accurate results.
Gas cost calculator
Gas Cost Calculator to estimate gasoline needed, trip fuel spend, and total driving cost by distance, mpg, and gas price.
Final Grade Calculator
Find the final exam score needed to reach a target grade or estimate the course result from an expected exam score.
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.
Document + PDF Converter
Convert supported documents to or from PDF while checking layout fidelity, fonts, page order, privacy, file limits, and output compatibility.
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.
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.
Cholesterol Ratio Calculator
Use the Cholesterol Ratio Calculator to estimate cholesterol ratios. Review inputs, results, limitations, safety guidance, and FAQs.
Density Calculator
Calculate density, mass, or volume with unit conversion, worked examples, and clear guidance about temperature, mixtures, and measurement precision.
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.
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.
Image Cropper
Crop JPG, PNG and WebP images with free or fixed ratios, exact dimensions, rotation, flipping and export controls.
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.
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.
Data Unit Converter
Convert bits and bytes across decimal and binary storage units while seeing the exact factor used for every result.
Fence Calculator
Estimate fence panels, posts and rails from route length, gates, section spacing and closed-perimeter conditions.
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.
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.
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.
Blood Type Calculator
Use the Blood Type Calculator to estimate possible child blood types. Review inputs, results, limitations, safety guidance, and FAQs.
Scientific Calculator
Evaluate scientific expressions involving powers, roots, logarithms, constants and trigonometric functions.
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.
Percentage of a Percentage Calculator
Percentage of a percentage calculator to find cumulative percentage and final value from two related percentage changes.
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.
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.
Fraction to Decimal Calculator
Convert a fraction to terminating or repeating decimal form and understand when rounding is required.
Balance Transfer Calculator
Compare a balance transfer’s fee, promotional period, payment plan, and post-promotion APR against keeping the current credit-card balance.
Weighted Grade Calculator
Calculate a weighted course grade from category percentages and weights, including the normalized grade so far and remaining weight.
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.
Proportion Calculator
Solve a missing value in equivalent ratios and verify the result using equal cross products.
Margin Calculator
Use this margin calculator to calculate gross profit, margin percentage, markup percentage, and missing price variable. Review inputs, formulas, examples, lim
Words per Minute Calculator
Use our Words Per Minute Calculator to estimate speaking time and reading time from word count, WPM speed, and result unit.
Mixed Number Calculator
Calculate with mixed numbers by converting whole-and-fraction parts to improper fractions and simplifying.
Tank Volume Calculator
Tank Volume Calculator helps you find tank capacity in gallons, liters, and cubic units with fast, accurate results.
Tile Calculator
Estimate tiles, edge cuts and full boxes using the project size, tile dimensions, grout gap and waste allowance.
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.
Theoretical Yield Calculator
Theoretical Yield Calculator to find the maximum product yield from stoichiometry, limiting reagent, and molar relationships.
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
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.
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.
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.
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,.
CGPA Calculator
Calculate cumulative CGPA from semester GPA and credit hours with a credit-weighted formula, worked example, and policy checks.
Image Color Picker
Pick an exact pixel from an uploaded image and copy its color in HEX, RGB, HSL, HSV, CMYK or OKLCH formats.
Personal Loan Calculator
Use this personal loan calculator to calculate estimated payment, total interest. Review key inputs, formulas, scenarios, limitations, 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.
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 CALCULATOR
Age Calculator helps you find exact age in years, months, and days from your date of birth instantly.
Circumference Calculator
Use our Circumference Calculator to find circle radius, diameter, circumference, and area from any one known value with unit conversions.
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
Dilution Ratio Calculator
Use our Dilution Ratio Calculator to calculate concentrate, water, final volume, or dilution ratio for water-to-concentrate mixes.
Loan Comparison Calculator
Use this loan comparison calculator to calculate monthly payment, total interest. Review key inputs, formulas, scenarios, limitations, 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.
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
Baby Growth Percentile Calculator
Estimate an infant growth percentile for weight, length or head circumference and learn how to interpret the trend.
Break-Even Calculator
Use this break-even calculator to calculate break-even units, break-even revenue. Review key inputs, formulas, scenarios, limitations, and FAQs.
Wallpaper Calculator
Estimate wallpaper strips and full rolls using wall height, perimeter, roll size, trimming and pattern repeat.
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.
PayPal Fee Calculator
Estimate transaction fees, net receipts, or a gross request amount using the current percentage and fixed fee for your transaction type.
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.
Acceleration Calculator
Calculate average acceleration from initial velocity, final velocity, and elapsed time while keeping direction, signs, and units consistent.
Cycling Calorie Calculator
Estimate calories burned while cycling from body weight, duration, pace and ride conditions, with guidance for interpreting MET-based results.