18 calculators for math, fitness, cooking, life events, school and recipe scaling.
No sign-up. No tracking. No ads.
Find out how much your meetings actually cost. Enter attendees, salaries, and duration.
Resize images and videos keeping proportions. Presets for YouTube, Reels, Instagram, DSLR.
Convert between units instantly. Length, weight, temperature, area, volume, speed, data size, time, CSS.
Convert between binary, octal, decimal, and hex. Live-linked fields. Bitwise inspector.
BMI, BMR, ideal weight, TDEE, and macros. Metric or imperial. US Navy body-fat method.
Convert between Roman numerals and regular numbers. Supports extended notation up to 3,999,999.
Three calculators in one: X % of Y, what % is X of Y, and percentage increase/decrease between two numbers.
Generate random integers in any range, one-off or in batch. Cryptographically random, unique option.
Convert between Celsius, Fahrenheit, Kelvin and Rankine. Live three-way conversion as you type.
Spell out any integer in English, from zero to quadrillions. Useful for cheques, legal text, and invoices.
Daily calorie needs using Mifflin-St Jeor. Activity multipliers + targets for cutting, maintaining and bulking.
Calculate due date and current pregnancy week from LMP or conception. Trimester breakdown + milestones.
Pace ↔ time ↔ distance. Split tables for 5K, 10K, half-marathon, marathon at any pace you set.
Cups ↔ grams ↔ ml ↔ oz with per-ingredient density. Plus °C / °F / gas-mark for oven temps.
Wake at the end of a 90-minute cycle (not mid-cycle). Bedtime suggestions or wake-time options.
Unweighted (4.0) + weighted (5.0) GPA from courses, grades, credits, and AP / honors / college flags.
MPG (US + UK), L/100km, km/L, cost-per-mile, full trip cost. Multi-currency.
Paste any recipe, change servings — every ingredient quantity scales. Fraction-aware, decimals or pretty fractions.
Mean, median, mode, range, sum and count from any list of numbers.
Add up work time from start/end rows, subtract breaks. Total in h:mm and decimal hours.
Simplify fractions, fraction to decimal and decimal to fraction, mixed numbers.
Simplify ratios to lowest terms and solve proportions A:B = C:?. Scale mixes and recipes.
Convert numbers to/from scientific, E-notation and engineering notation.
Area, circumference, radius and diameter from any single value.
Area (Heron), perimeter, type and right-angle check from three sides.
Solve a² + b² = c² for the missing side of a right triangle.
Greatest common divisor (HCF) and least common multiple of two or more numbers.
Check if a number is prime and get its prime factorization.
Population & sample standard deviation, variance and mean from a number list.
nCr (combinations), nPr (permutations) and factorials from n and r.
Compare products by price per unit, find the cheapest option at the shelf.
Slope, distance, midpoint and y=mx+b from two points (x1,y1) and (x2,y2).
Solve ax²+bx+c=0: roots (real or complex), discriminant and vertex.
Click counter with keyboard support & custom step. Count is saved in your browser.
List N Fibonacci terms from any start point, exact big-integer math, one-click copy.
Break a number into its prime factors, in exponent form (360 = 2³ × 3² × 5).
Compute n! exactly with big-integer math, plus the digit count.
Interest & total from principal, rate and time (I = P·r·t).
Mean, median, mode, range, sum, min and max from any list of numbers.
Weighted mean from values and weights, plus the plain average for comparison.
Raise a base to any exponent, with exact integer results and scientific notation.
Square root, cube root or any nth root of a number, with a verification check.
Log of a number in any base, with presets for 10, e and 2.
Remainder and quotient of a division, including the always-positive Euclidean modulo.
Daily calories plus protein, carb and fat grams from your body, activity and goal.
Estimate your 1RM from weight and reps, with a training-percentage table.
Healthy weight estimate for your height and sex from four classic formulas.
Estimate body fat from tape measurements (US Navy method), with category and lean mass.
Daily water target from your weight and exercise, in litres, cups and ounces.
Max heart rate and five training zones in bpm, with optional Karvonen method.
Daily calorie deficit and weekly loss to hit a goal weight in your timeframe.
Estimate your fertile window, ovulation day and next periods from your cycle.
How much paint a room needs from its size, coats and coverage. Litres and gallons.
How many tiles you need from the area and tile size, plus a waste allowance.
Concrete volume for a slab and the number of pre-mix bags needed.
How many boxes of laminate or vinyl flooring you need from area and coverage.
Total questions + number wrong → percentage score and letter grade, instantly.
What you need to score on the final to hit your target grade.
Overall grade from categories with different weights (homework, quizzes, exams).
Solve a/b = c/d for the missing value by cross-multiplication (rule of three).
Split a length by the golden ratio (φ ≈ 1.618), or find the matching part.
Count significant figures in a number and round to N sig figs. For science and homework.
A broad collection of free online calculators for math, fitness, cooking, life events, school, finance and everyday conversions. From the basics (percentage, temperature, BMI) to the specialized (TDEE, running pace, recipe scaling, Roman numerals). Browser-based, no sign-up, no ads.
Yes — every calculator in this category is free, no sign-up, no usage limits. No data is uploaded; every calculation runs in your browser.
Yes — BMI, cooking, running pace, gas mileage and the unit converter all support both. Temperature converter handles Celsius, Fahrenheit, Kelvin and Rankine.
The BMI / TDEE calculators use Mifflin-St Jeor (the most accurate formula for general populations) and standard activity multipliers. They're informational; consult a doctor for medical decisions.
For most tools, no — the inputs are local to your browser. The few that benefit from sharing (random number generator with a seed, for example) explicitly support it.