What this calculator does
Toothpaste tube life works out how many days a toothpaste tube lasts a household, from tube size and brushing habits. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaDaily use = amount per brushing × brushings per day × people; days remaining = tube volume ÷ daily use
The inputs explained
| Field | What to enter |
|---|---|
| Tube size (ml) | A number, measured in ml. Starts at 100. |
| Amount per brushing (pea-sized ≈0.25 ml) (ml) | A number, measured in ml. Starts at 0.25. |
| Brushings per day, per person | A number. Starts at 2. |
| People sharing the tube | A number. Starts at 1. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with tube size
Every other input is held at the calculator’s starting values while tube size varies. Select any row to load that scenario into the calculator.