Free Tools

Simple, no-sign-up calculators to help you build better habits and understand your body. Free forever — because accountability shouldn't cost anything.

Habits & Focus

Habit Formation Calculator
How many days until your new habit becomes automatic — based on the real 66-day research.
1% Better Every Day Calculator
See how tiny daily gains compound into 37x over a year.
Screen Time Cost Calculator
What your daily scrolling adds up to — in days, weeks, and books.
What Could You Achieve?
Turn the hours you waste into skills you could learn instead.
Reading Time Calculator
When you'll finish a book — and how many you'd read in a year.

Health & Fitness

TDEE Calculator
Your daily calorie needs to lose, maintain, or gain — Mifflin-St Jeor.
BMI & Body Fat Calculator
Your BMI, weight category, and estimated body fat percentage.
Water Intake Calculator
How much water you need by weight, activity, and climate.
Running Pace Calculator
Pace per km and mile, plus 5K–marathon race predictions.
Sleep Cycle Calculator
The best times to fall asleep or wake — by 90-minute cycles.

Built by the team behind Groop

Groop is a social habit app — a small group of friends keeping each other on track with daily photo check-ins. Get notified when we launch on iOS.

You're on the list. See you at launch.

First 1,000 sign-ups get 3 months Groop+ free. No spam, ever.