Free tools

Simple calculators, no account and no ads. They run entirely in your browser — nothing you type is sent anywhere.

• Sleep debt calculatorHow much sleep you lost over a week and how long a realistic catch-up takes.
• Breathing pace calculatorHow many breaths a minute a chosen pattern gives you, and how long a full session runs.
• Habit time cost calculatorWhat a daily few-minute habit adds up to over a year, and what the time could buy instead.