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.
Teen BMI calculator
Use the Teen BMI calculator to estimate a teen BMI percentile. Review inputs, results, limitations, safety guidance, and FAQs.
Molarity Calculator
Use our Molarity Calculator to find moles, mass concentration, and molarity from solute mass, molar mass, and solution volume.
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.
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.
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.
Roof Pitch Calculator
Roof Pitch Calculator helps you find roof pitch, slope, angle, and rise-to-run values quickly for roofing, planning, and construction work.
Velocity Calculator
Calculate average velocity, displacement, or elapsed time with unit conversion and clear guidance about direction and the difference between speed and velocity.
CPM Calculator
Use this cpm calculator to calculate cost per thousand impressions, implied cost, or required impressions. 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,
Triangle Calculator
Solve a triangle’s missing sides, angles, area and perimeter from sufficient known measurements.
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.
Harris-Benedict Calculator (Basal Metabolic Rate)
Use the Harris-Benedict Calculator to estimate basal metabolic rate. Review inputs, results, limitations, safety guidance, and FAQs.
Mortgage Interest Calculator
Use this mortgage interest calculator to calculate estimated interest by period, total interest. Review key inputs, formulas, scenarios, limitations, and.
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.
Paver Calculator
Estimate whole pavers for a patio or walkway using actual dimensions, joint width, pattern and cutting waste.
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.
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.
Image Converter Pro
Convert images among supported formats while managing quality, transparency, dimensions, metadata, file size, and browser compatibility.
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.
Korean Age Calculator
Korean Age Calculator helps you convert your age using the traditional Korean age system quickly and clearly.
Exponent Calculator
Exponent Calculator helps you solve powers, positive and negative exponents, and exponential values quickly with clear, accurate results.
Long Division Calculator
Perform long division with a quotient, remainder and step-by-step divide-multiply-subtract work.
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
PayPal Fee Calculator
Estimate transaction fees, net receipts, or a gross request amount using the current percentage and fixed fee for your transaction type.
Marathon Pace Calculator
Use this marathon pace calculator to estimate required average pace, speed, and checkpoint splits. Learn the inputs, formulas, examples, limitations, training
Paint Calculator
Estimate wall-paint quantity from room dimensions, openings, coats, coverage and a practical allowance.
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 & 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
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
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.
Asphalt Calculator
Estimate compacted asphalt volume and tonnage from paving area, thickness, density and ordering allowance.
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
Stair Calculator
Estimate uniform risers, tread count, total run, angle and stringer length for a straight stair concept.
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.
Significant Figures Calculator
Use our Significant Figures Calculator to count sig figs, round numbers or expressions, and show decimal, scientific, and E notation.
Dilution Ratio Calculator
Use our Dilution Ratio Calculator to calculate concentrate, water, final volume, or dilution ratio for water-to-concentrate mixes.
Calories Burned Calculator
Use this calories burned calculator to estimate estimated exercise energy expenditure in calories. Learn the inputs, formulas, examples, limitations, training
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.
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,.
Percentage to CGPA Calculator
Convert percentage to CGPA using proportional, legacy 9.5, or custom institutional methods, with scale checks and policy guidance.
Refinance Calculator
Use this refinance calculator to calculate estimated payment change, interest difference. Review key inputs, formulas, scenarios, limitations, and FAQs.
Acceleration Calculator
Calculate average acceleration from initial velocity, final velocity, and elapsed time while keeping direction, signs, and units consistent.
Debt Payoff Calculator
Use this debt payoff calculator to calculate estimated payoff date, total interest. Review key inputs, formulas, scenarios, limitations, and FAQs.
Theoretical Yield Calculator
Theoretical Yield Calculator to find the maximum product yield from stoichiometry, limiting reagent, and molar relationships.
Credit Card Interest Calculator
Estimate credit card interest, payoff time, and total repayment cost using balance, APR, payment amount, and compounding assumptions.
Fence Calculator
Estimate fence panels, posts and rails from route length, gates, section spacing and closed-perimeter conditions.
Savings Goal Calculator
Use this savings goal calculator to calculate required periodic saving, projected growth. 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.
Grams To Ounces Calculator
Use our Grams to Ounces Calculator to convert grams to ounces, ounces to grams, kilograms, milligrams, and troy ounces.
Data Unit Converter
Convert bits and bytes across decimal and binary storage units while seeing the exact factor used for every result.
Net Worth Calculator
Use this net worth calculator to calculate total assets, total liabilities. Review key inputs, formulas, scenarios, limitations, and FAQs.
Percentage Increase Calculator
Find the percentage increase between two numbers. Enter original and new values to get % increase, change amount, and final value. Reverse solve from % too. Instant steps & PDF.
CGPA Calculator
Calculate cumulative CGPA from semester GPA and credit hours with a credit-weighted formula, worked example, and policy checks.
Margin Calculator
Use this margin calculator to calculate gross profit, margin percentage, markup percentage, and missing price variable. Review inputs, formulas, examples, lim
Interest Rate Calculator
Solve for interest rate, principal, balance, or time while distinguishing simple, compound, nominal, and effective rate 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.
Image Color Picker
Pick an exact pixel from an uploaded image and copy its color in HEX, RGB, HSL, HSV, CMYK or OKLCH formats.
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
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.
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.
Grams To Calories Calculator
Estimate calories from grams of carbohydrate, protein, fat, or alcohol. Review energy factors, examples, label limitations, and six practical FAQs.
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.
Surface Area Calculator
Find lateral or total surface area for common three-dimensional solids in square units.
Child Height Percentile Calculator
Use the Child Height Percentile Calculator to estimate a child height percentile. Review inputs, results, limitations, safety guidance, and FAQs.
Alcohol Dilution Calculator
Use the Alcohol Dilution Calculator to estimate final volume and diluent needed from starting and target ABV, with formula, examples, safety notes, and FAQs.
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
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.
Circle Skirt Calculator
Circle Skirt Calculator to find waist radius, hem measurements, and fabric requirements for full, half, or quarter skirts.
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.
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.
Free AVIF Image Converter
Easily convert AVIF images to JPG, PNG, or WebP formats with our user-friendly tool. Fast, efficient, and free for all your image conversion needs.
Fraction to Percentage Calculator
Convert fractions to percentages and percentages to simplified fractions. Enter numerator, denominator, or percent to get quick live results.
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.
Free SVG Converter
Use the embedded SVG converter below. Check the tool for its available options and instructions.
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.
Blood Type Calculator
Use the Blood Type Calculator to estimate possible child blood types. Review inputs, results, limitations, safety guidance, and FAQs.
Dividend Calculator
Use this dividend calculator to calculate periodic and annual dividend income, yield, and projected reinvestment growth. Review inputs, formulas, examples, li
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.
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.
Free JPG to PNG Converter
Convert JPG images to PNG format with the embedded converter on this page.
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.
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.
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.
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.
Maintenance Calorie Calculator
Use the Maintenance Calorie Calculator to estimate maintenance calories. Review inputs, results, limitations, safety guidance, and FAQs.
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
FFMI Calculator (Fat-Free Mass Index)
Use the FFMI Calculator to estimate fat-free mass index. Review inputs, results, limitations, safety guidance, 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.
BTU Calculator
Estimate a preliminary room heating or cooling load from volume, temperature difference and major adjustments.
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.
Budget Calculator
Use this budget calculator to calculate monthly surplus or deficit, category totals. Review key inputs, formulas, scenarios, limitations, and FAQs.
IQ PERCENTILE CALCULATOR
Use our IQ Percentile Calculator to convert an IQ score into percentile rank, percent above, and percent below using SD 15 or SD 16 normal-distribution scales.
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.
Helium Balloons Calculator
Use our Helium Balloons Calculator to estimate lift per balloon, total helium volume, and how many helium balloons you need to lift a given weight.
Mulch Calculator
Calculate mulch volume and full bags from landscape-bed area and the finished depth you intend to maintain.
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.
Balance Transfer Calculator
Compare a balance transfer’s fee, promotional period, payment plan, and post-promotion APR against keeping the current credit-card balance.
Commission Calculator
Use this commission calculator to calculate commission earned and combined compensation. Review key inputs, formulas, scenarios, limitations, and FAQs.