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.
Search a Tool
01
Calculators and tools
Find calculators, converters, and practical tools to simplify everyday tasks, solve math problems, and plan projects.
02
Useful categories
Explore finance, health, math, science, construction, and more—all organized to help you find the right tool.
03
Free to use
Use free online calculators and converters for everyday questions, quick checks, and practical planning.
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.
Long Division Calculator
Perform long division with a quotient, remainder and step-by-step divide-multiply-subtract work.
Image Color Picker
Pick an exact pixel from an uploaded image and copy its color in HEX, RGB, HSL, HSV, CMYK or OKLCH formats.
Stride Length Calculator
Use this stride length calculator to estimate average stride or step length in chosen units. Learn the inputs, formulas, examples, limitations, training tips,
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.
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.
Lease Calculator
Use this lease calculator to calculate estimated monthly lease payment, depreciation charge. Review key inputs, formulas, scenarios, 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.
Image Compressor
Compress JPG, PNG, WebP, and SVG images in your browser. Choose JPEG or WebP output, adjust quality, resize dimensions, and download.
Fraction to Decimal Calculator
Convert a fraction to terminating or repeating decimal form and understand when rounding is required.
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.
Door and Window Area Calculator
Total rectangular door and window opening area and perimeter while distinguishing unit and rough-opening sizes.
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
Topsoil Calculator
Estimate topsoil volume, bags or mass from the measured area, fill depth and the supplier’s product information.
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.
Percentage of a Percentage Calculator
Percentage of a percentage calculator to find cumulative percentage and final value from two related percentage changes.
Final Grade Calculator
Find the final exam score needed to reach a target grade or estimate the course result from an expected exam score.
Pressure Calculator
Calculate pressure, force, or area with common pressure-unit conversions and guidance about normal force, area, and gauge versus absolute pressure.
Grams To Calories Calculator
Estimate calories from grams of carbohydrate, protein, fat, or alcohol. Review energy factors, examples, label limitations, and six practical FAQs.
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.
Fuel Cost Calculator
Fuel Cost Calculator to estimate fuel used and total trip expense from distance, fuel efficiency, and fuel price.
Interest Rate Calculator
Solve for interest rate, principal, balance, or time while distinguishing simple, compound, nominal, and effective rate assumptions.
Image Converter Pro
Convert images among supported formats while managing quality, transparency, dimensions, metadata, file size, and browser compatibility.
Protein Calculator
Estimate a daily protein range from body weight, activity and goal for general nutrition planning.
One Rep Max Calculator
Estimate your one-repetition maximum from a completed submaximal set and translate it into practical training percentages.
Dose Calculator
Check dose arithmetic from an already verified prescription or label, including mg/kg, total mg and liquid volume conversions.
Salary to Hourly Calculator
Use this salary to hourly calculator to calculate equivalent monthly, weekly, daily, and hourly gross pay. Review inputs, formulas, examples, limitations, and
Blood Type Calculator
Use the Blood Type Calculator to estimate possible child blood types. Review inputs, results, limitations, safety guidance, and FAQs.
Winning Percentage Calculator
Use this winning percentage calculator to estimate winning percentage, total games, and record comparisons. Learn the inputs, formulas, examples, limitations,
Tile Calculator
Estimate tiles, edge cuts and full boxes using the project size, tile dimensions, grout gap and waste allowance.
Cycling Calorie Calculator
Estimate calories burned while cycling from body weight, duration, pace and ride conditions, with guidance for interpreting MET-based results.
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.
Stock Calculator
Use this stock calculator to calculate cost basis, proceeds, gain or loss, and percentage return. Review inputs, formulas, examples, limitations, and FAQs.
Average Percentage Calculator
Average percentage calculator to find simple or weighted averages of multiple percentages with quick, accurate results.
Grams To Ounces Calculator
Use our Grams to Ounces Calculator to convert grams to ounces, ounces to grams, kilograms, milligrams, and troy ounces.
Half-Life Calculator
Calculate remaining quantity, elapsed time, half-life, decay constant, or mean lifetime with formulas, steps, units, and a worked example.
Fraction Calculator
Calculate fraction operations, simplify the result and understand common denominators and reciprocals.
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.
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.
t-statistic Calculator
Use our t-Statistic Calculator to compute the t value, degrees of freedom, and standard error for one-sample, two-sample, Welch, pooled, or paired t-tests.
BTU Calculator
Estimate a preliminary room heating or cooling load from volume, temperature difference and major adjustments.
Favicon Generator
Turn one logo or image into ICO, PNG and app-icon files with crop, padding, mask and background controls.
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.
Confidence Interval Calculator
Use our Confidence Interval Calculator to find confidence intervals for a mean or proportion with standard error, critical value, margin of error, and lower and upper bounds.
Probability Calculator
Calculate event probabilities, complements, unions and intersections while checking independence 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.
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
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.
VAT Calculator
Use this vat calculator to calculate tax amount, price before tax, and price including tax. Review inputs, formulas, examples, limitations, and FAQs.
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.
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.
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.
PayPal Fee Calculator
Estimate transaction fees, net receipts, or a gross request amount using the current percentage and fixed fee for your transaction type.
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
SLEEP CALCULATOR
Plan a bedtime or wake-up time using target sleep duration and estimated cycles, with realistic guidance about sleep latency and individual needs.
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.
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 Predictor
Use the Child Height Predictor to estimate an adult-height estimate for a child. Review inputs, results, limitations, safety guidance, and FAQs.
ABSI (A Body Shape Index) Calculator
Use the ABSI Calculator to estimate A Body Shape Index. Review inputs, results, limitations, safety guidance, and FAQs.
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
FFMI Calculator (Fat-Free Mass Index)
Use the FFMI Calculator to estimate fat-free mass index. Review inputs, results, limitations, safety guidance, and FAQs.
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.
VO₂ Max Calculator
Use this vo₂ max calculator to estimate estimated aerobic capacity in milliliters of oxygen per kilogram per minute. Learn the inputs, formulas, examples, lim
Proportion Calculator
Solve a missing value in equivalent ratios and verify the result using equal cross products.
Period Calculator
Predict your next period start/end, ovulation day, and fertile window from LMP and cycle length with this free period calculator.
Theoretical Yield Calculator
Theoretical Yield Calculator to find the maximum product yield from stoichiometry, limiting reagent, and molar relationships.
Roofing Shingle Calculator
Estimate sloped roof area, roofing squares and bundles from footprint, pitch and a complexity allowance.
Refinance Calculator
Use this refinance calculator to calculate estimated payment change, interest difference. Review key inputs, formulas, scenarios, limitations, and FAQs.
Work Calculator
Calculate mechanical work using force, displacement, and the angle between them, with sign conventions, examples, and unit guidance.
Velocity Calculator
Calculate average velocity, displacement, or elapsed time with unit conversion and clear guidance about direction and the difference between speed and velocity.
BMI Calculator (Body Mass Index)
Use the BMI Calculator to estimate adult body mass index. Review inputs, results, limitations, safety guidance, and FAQs.
Water Intake Calculator
Estimate a general daily hydration target from body weight, activity and climate, with practical guidance on interpreting the result.
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.
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
Sand Calculator
Use our Sand Calculator to estimate sand area, volume, weight, and optional total cost from length, width, depth, density, and price.
Decimal to Fraction Calculator
Convert terminating or repeating decimals to reduced fractions and mixed-number form.
Avogadro’s number calculator
Convert between moles and representative particles using the exact Avogadro constant, with examples for atoms, molecules, ions, and formula units.
Area Calculator
Calculate the area of common two-dimensional shapes using dimensions in compatible units.
Plastic Footprint Calculator
Estimate annual household plastic use in kilograms and pounds from common disposable items, frequencies and model item weights.
Free JPG to PNG Converter
Convert JPG images to PNG format with the embedded converter on this page.
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.
LCM Calculator
Find the least common multiple of integers using prime factors or the relationship between LCM and GCF.
Creatinine Clearance Calculator
Estimate creatinine clearance with the Cockcroft-Gault equation and review the assumptions, units and limitations behind the result.
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.
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.
Free HEIC Converter
Use the HEIC converter below. Check the tool for available conversion options and follow its on-screen guidance.
Gravel Calculator
Use our Gravel Calculator to estimate gravel volume, weight, tons, cubic yards, coverage, and total cost from area, depth, density, and price.
Drywall Calculator
Estimate whole drywall sheets for walls and an optional ceiling using room dimensions, panel size and waste.
Dividend Calculator
Use this dividend calculator to calculate periodic and annual dividend income, yield, and projected reinvestment growth. Review inputs, formulas, examples, li
Brick Calculator
Estimate brick quantity from net wall area, the brick face, mortar joint, openings and practical waste.
GPA calculator
Calculate semester GPA and estimate cumulative GPA from course grade points and credit hours, with clear formulas and policy guidance.
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.
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
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.
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.
CGPA Calculator
Calculate cumulative CGPA from semester GPA and credit hours with a credit-weighted formula, worked example, and policy checks.
Baby Growth Percentile Calculator
Estimate an infant growth percentile for weight, length or head circumference and learn how to interpret the trend.
CGPA to Percentage Calculator
Convert CGPA to percentage with proportional, legacy 9.5, or custom institutional methods, plus clear policy guidance and examples.
Margin Calculator
Use this margin calculator to calculate gross profit, margin percentage, markup percentage, and missing price variable. Review inputs, formulas, examples, lim
Quadratic Formula Calculator
Solve a quadratic equation from coefficients a, b and c and interpret its discriminant and roots.