Free online calculators

Simple browser stopwatch with lap times. Tentaco Stopwatch: review input and get an instant result — free, no sign-up.

Find the greatest common divisor and least common multiple. Tentaco GCD & LCM Calculator: review input and get an instant result — free, no sign-up.

Add or subtract days from a date. Tentaco Add Days to Date: review input and get an instant result — free, no sign-up.

Estimate trip fuel cost from distance, consumption and price. Tentaco Fuel Cost Calculator: review input and get an instant result — free, no sign-up.

Compute n! for any non-negative integer. Tentaco Factorial Calculator: review input and get an instant result — free, no sign-up.

Flip a virtual coin one or many times. Tentaco Coin Flip: review input and get an instant result — free, no sign-up.

Count days until a target date. Tentaco Days Until Date: review input and get an instant result — free, no sign-up.

Split a bill with tip among people. Tentaco Split Bill: review input and get an instant result — free, no sign-up.

Calculate Body Mass Index in metric or imperial units. Tentaco BMI Calculator: review input and get an instant result — free, no sign-up.

Work out percentages, increases, decreases and ratios. Tentaco Percentage Calculator: review input and get an instant result — free, no sign-up.

Calculate exact age in years, months and days from a birth date. Tentaco Age Calculator: review input and get an instant result — free, no sign-up.

Calculate dimensions that keep an aspect ratio. Tentaco Aspect Ratio Calculator: review input and get an instant result — free, no sign-up.

Estimate download duration from file size and speed. Tentaco Download Time: review input and get an instant result — free, no sign-up.

Estimate basal metabolic rate (Mifflin-St Jeor). Tentaco BMR Calculator: review input and get an instant result — free, no sign-up.

Calculate binomial combinations. Tentaco Combinations nCr: review input and get an instant result — free, no sign-up.

Calculate the time between two dates. Tentaco Date Difference Calculator: review input and get an instant result — free, no sign-up.

Roll virtual dice with custom sides. Tentaco Dice Roller: review input and get an instant result — free, no sign-up.

Great-circle distance between coordinates. Tentaco Distance Calculator: review input and get an instant result — free, no sign-up.

Generate a Fibonacci number sequence. Tentaco Fibonacci Generator: review input and get an instant result — free, no sign-up.

Project future value and purchasing power loss with compound inflation. Tentaco Inflation Calculator: review input and get an instant result — free, no sign-up.

Pick random unique lottery numbers. Tentaco Lottery Number Picker: review input and get an instant result — free, no sign-up.

Basic statistics from a number list. Tentaco Mean, Median, Mode: review input and get an instant result — free, no sign-up.

Convert between pace, speed, distance and time. Tentaco Running Pace Calculator: review input and get an instant result — free, no sign-up.

Calculate percent change between two values. Tentaco Percentage Change: review input and get an instant result — free, no sign-up.

Calculate ordered permutations. Tentaco Permutations nPr: review input and get an instant result — free, no sign-up.

25/5 minute focus timer with alerts. Tentaco Pomodoro Timer: review input and get an instant result — free, no sign-up.

Check if a number is prime and list its factors. Tentaco Prime Number Checker: review input and get an instant result — free, no sign-up.

Break a number into prime factors. Tentaco Prime Factorization: review input and get an instant result — free, no sign-up.

Solve ax² + bx + c = 0. Tentaco Quadratic Solver: review input and get an instant result — free, no sign-up.

Generate random numbers within a range, optionally unique. Tentaco Random Number Generator: review input and get an instant result — free, no sign-up.

Solve proportions like 3:4 = 6:x. Tentaco Ratio Calculator: review input and get an instant result — free, no sign-up.

Estimate final balance with initial deposit, monthly savings and return rate. Tentaco Savings Plan Calculator: review input and get an instant result — free, no sign-up.

Find the best times to wake up or go to sleep. Tentaco Sleep Cycle Calculator: review input and get an instant result — free, no sign-up.

Compute mean and standard deviation. Tentaco Standard Deviation: review input and get an instant result — free, no sign-up.

Convert net and gross amounts with German VAT rates (0%, 7%, 19%). Tentaco Tax Calculator (DE): review input and get an instant result — free, no sign-up.

Daily water intake from body weight. Tentaco Water Intake: review input and get an instant result — free, no sign-up.

Get ISO week number for a date. Tentaco Week Number: review input and get an instant result — free, no sign-up.

Count weekdays between two dates. Tentaco Workdays Between: review input and get an instant result — free, no sign-up.

Math, dates, health and utility calculators in one workspace. Tentaco Calculator Studio: review input and get an instant result — free, no sign-up.

Pomodoro, sleep cycles, tips and everyday calculators. Tentaco Productivity Studio: review input and get an instant result — free, no sign-up.

Reading time, markdown preview and quiz data. Tentaco Education Studio: review input and get an instant result — free, no sign-up.

Multi-step presets, pipeline builder and file pipelines. Tentaco Workflow Studio: review input and get an instant result — free, no sign-up.

Percentage, loan, BMI, tip, age and unit converters — instant browser calculators.

Loans, percentages, fees and money maths — clear finance helpers that run in your browser.

Convert metric, imperial and scientific units instantly in browser.