Free calculators that run in your browser
Fast everyday calculators for percentages, BMI, loans, tips, ages, dates and unit conversions โ 100% in your browser with no uploads or signup.
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Percentage Calculator
Calculate percentages, percentage share and percent change instantly.
BMI Calculator
Find body mass index with metric or imperial units and see the category.
Loan Calculator
Estimate monthly payment, total interest and total paid for a fixed-rate loan.
Tip Calculator
Split a bill with tip and see the total and per-person amount.
Age Calculator
Calculate exact age in years, months and days plus time until next birthday.
Date Difference Calculator
Count days, weeks, months and years between two calendar dates.
Unit Converter
Convert length, weight, temperature and data-size units locally.
Compound Interest Calculator
Estimate compound growth, contributions, final balance and interest earned.
Discount Calculator
Calculate sale price, savings and reverse discounts from percent or amount off.
Sales Tax Calculator
Add sales tax or remove included VAT from a gross price.
Hours Calculator
Calculate hours worked from start, end and break times with optional pay.
Calorie Calculator
Estimate BMR, TDEE and daily calorie targets with metric or imperial inputs.
Scientific Calculator
Evaluate arithmetic, powers, roots, trig, logs, constants and parentheses safely.
Fraction Calculator
Add, subtract, multiply or divide fractions with simplified results.
Ratio Calculator
Simplify ratios, solve missing proportion terms and find scale factors.
Aspect Ratio Calculator
Compute matching dimensions for common or custom aspect ratios.
GPA Calculator
Calculate weighted GPA from grades and credits with an editable 4.0 mapping.
Statistics Calculator
Calculate mean, median, mode, range, variance and standard deviation from pasted numbers.
Roman Numeral Converter
Convert numbers to Roman numerals and validate Roman numerals back to numbers.
Cooking Converter
Convert cups, tablespoons, teaspoons, millilitres, grams and ounces with ingredient density presets.
Area & Volume Calculator
Calculate area and volume for rectangles, circles, triangles, cylinders, spheres and cones.
Speed Distance Time Calculator
Solve for speed, distance or time from the other two values with flexible unit options.
Margin & Markup Calculator
Compute price, cost, margin, markup and profit from any two known values.
Combinations & Permutations Calculator
Calculate nCr combinations, nPr permutations and factorials with the formulas shown.
Electricity Cost Calculator
Estimate daily, monthly and yearly running cost from device watts, hours and price per kWh.
Concrete Calculator
Calculate concrete volume for slabs, footings, columns, walls and stairs, plus premix bags.
Paint Calculator
Estimate litres or gallons of paint and cans needed from room size, openings and coats.
Tile Calculator
Find how many tiles and boxes you need from area, tile size, grout gap and waste.
Fuel Cost Calculator
Estimate trip fuel and cost from distance, efficiency and price, with round trip and split.
Ohm's Law Calculator
Find voltage, current, resistance and power from any two known values with SI units.
Voltage Drop Calculator
Calculate cable voltage drop for copper or aluminium wire and find the minimum AWG or mmยฒ size.
Final Grade Calculator
Find the score you need on the final exam to reach your target grade.
Weighted Average Calculator
Calculate a weighted mean from values and weights pasted from a list or spreadsheet.
Rounding & Significant Figures Calculator
Round to decimal places, significant figures or a multiple with half up, banker's, ceiling or floor.
Long Division Calculator
Divide step by step with the written layout, remainders, decimals and repeating digits.
Percent Error Calculator
Calculate percent error, percentage difference or percent change between two values.
Number to Words Converter
Spell numbers in English words, cheque/check amounts, currency and ordinals.
Average Calculator
Find the mean, median, mode, midrange, geometric and harmonic mean of any list of numbers.
Standard Deviation Calculator
Sample and population standard deviation, variance, standard error and a step-by-step deviation table.
Percentage Increase & Decrease Calculator
Find percent change, increase or decrease a number by a percent, or work back to the original value.
Square Footage Calculator
Area of rectangles, triangles, circles, trapezoids and L-shapes in sq ft, mยฒ, sq yd and acres.
Flooring Calculator
Work out flooring area, waste, boxes, planks and cost for any room.
Mulch, Gravel & Soil Calculator
Cubic yards or metres, weight, bags and cost of mulch, soil, sand or gravel for a given area and depth.
Watts, Amps & Volts Calculator
Solve power, current or voltage for DC, single-phase and three-phase AC with power factor.
kWh Calculator
Calculate kilowatt-hours and cost from power and time, or convert between kWh, MJ, BTU and more.
MPG Calculator
Fuel economy in MPG (US and UK), L/100 km and km/L, with cost per mile and a unit converter.
Unit Price Calculator
Compare the price per kg, litre or item across sizes and brands to find the best deal.
Recipe Scaler
Scale a recipe up or down to any number of servings, with fractions and mixed numbers handled.
LCM & GCF Calculator
Find the least common multiple and greatest common factor of several numbers with steps.
Pythagorean Theorem Calculator
Solve a right triangle: find a leg or the hypotenuse, plus area, perimeter and angles.
Drywall Calculator
Estimate drywall sheets, joint compound, tape and screws for a room or wall.
Fence Calculator
Estimate fence posts, rails, panels or pickets from the fence length and spacing.
BTU Calculator
Estimate the BTU cooling or heating capacity needed for a room from its size and conditions.
Resistor Color Code Calculator
Decode 4, 5 and 6 band resistor colors into ohms, tolerance and temperature coefficient.
Number Base Converter
Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36.
Quadratic Equation Solver
Solve axยฒ + bx + c = 0 with discriminant, real or complex roots, vertex and steps.
Hourly to Salary Calculator
Convert an hourly wage to weekly, monthly and yearly salary, or a salary to hourly pay.
Density Calculator
Solve density, mass or volume from the other two values with common material presets.
Sig Fig Calculator
Count significant figures, round to sig figs and add, subtract, multiply or divide with sig fig rules.
Dog Age Calculator
Convert your dog's age to human years by breed size or with the modern UC San Diego formula.
Cat Age Calculator
Convert your cat's age to human years and see its life stage from kitten to senior.
Decimal to Fraction Converter
Convert any decimal to a simplified fraction or mixed number, with steps and optional denominator limit.
Fraction to Decimal Converter
Convert fractions and mixed numbers to decimals and percents, showing repeating digits.
Percent to Fraction Converter
Convert any percentage to a simplified fraction, decimal and mixed number with the working shown.
Molar Mass Calculator
Calculate molar mass from any chemical formula, with element breakdown, mass percent and grams-to-moles.
Accurate everyday calculations, without sending data anywhere
Calc Tools is a collection of simple calculators for numbers you need often: percentages, BMI, loan payments, tips, ages, date spans and unit conversions. Each tool runs entirely in your browser, so the numbers you type stay on your device and results update instantly.
Start with the percentage calculator for discounts and growth rates, estimate payments with the loan calculator, or convert common measurements in the unit converter. No accounts, no uploads, no external APIs and no live-rate dependencies โ just quick client-side math.