Toothbrush Replacement Calculator

Toothbrush Replacement Calculator: Track Your Replacement Schedule

It's easy to lose track of exactly when you last swapped toothbrushes, and worn bristles clean far less effectively. This calculator tracks the days since your last replacement against the commonly recommended 90-day interval.

The Formula

Days Used = Today − Last Replaced Date, Days Remaining = Recommended Interval − Days Used

Worked Example

Last replaced on May 1, 2026, checked on July 19, 2026, with the standard 90-day recommendation.

Days Used = 79, Days Remaining = 90 − 79 = 11 days until replacement is due

How to Use This Calculator

  1. Enter the date you last replaced your toothbrush.
  2. Optionally adjust the recommended replacement interval (90 days by default).
  3. Click Calculate to see how many days remain, or how overdue you are.

Related Calculations

Use with the Toothpaste Tube Lifespan Calculator for a complete oral care supply schedule.