Free calculators that run in your browser
Fast everyday calculators for percentages, BMI, loans, tips, ages, dates and unit conversions — 100% in your browser with no uploads or signup.
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.
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 — just quick client-side math.