# Toothpaste Calculator

URL: https://speedycalculator.com/calculators/everyday-life/toothpaste/
Last updated: 2026-10-25

> The toothpaste calculator works out how long a tube of toothpaste lasts for your household and how much you spend on toothpaste per month and per year.

## Inputs

- Tube size (mL, fl oz)
- Amount per brushing (pea-sized portions)
- Brushes per day
- People
- Wastage (%)
- Price per tube

## Results

- Toothpaste used per day
- Days per tube
- Tubes per year
- Cost per year

## Formula

```
Use per day = people × brushes per day × amount per brush (pea-sized ≈ 0.25 mL) × (1 + waste)
Days per tube = tube volume ÷ daily use
Cost per year = tube price × 365.25 ÷ days per tube
```

## Explanation

Dentists recommend a pea-sized amount of toothpaste (about 0.25 g) for children and a little more for adults, twice a day. Many adults use a full strip along the brush – three or four times as much as needed – which makes tubes run out quickly.

### How to use the Toothpaste Calculator

- **Tube size**
- **Amount per brushing (pea-sized portions)**
- **Brushes per day**
- **People**
- **Wastage**
- **Price per tube**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the tube size, the amount per brushing in pea-sized portions, brushes per day, people, wastage and the price per tube.

### Tips

- Use the amounts printed on the product (ml, sheets, applications) where available.
- Count everyone in the household who shares the product.
- Buy a little extra so you never run out unexpectedly.
- Small daily habits add up – check the yearly figures for the real impact.

### Common mistakes to avoid

- Forgetting that hot water costs energy as well as water.
- Underestimating how much sunscreen a full application needs.
- Comparing pack prices without checking the size of each pack.

### Inputs explained

FieldWhat to enterTube sizeUnits: mL, fl ozAmount per brushing (pea-sized portions)A numberBrushes per dayA numberPeopleA numberWastageIn %Price per tubeAmount in your currency

### What each result means

- **Toothpaste used per day** = [People]×[Brushes per day]×[Amount per brushing (pea-sized portions)]×0.25e-6×(1 + [Wastage]÷100)
- **Days per tube** = [Tube size]÷[Toothpaste used per day]
- **Tubes per year** = 365.25÷[Days per tube]
- **Cost per year** = [Tubes per year]×[Price per tube]

### Example values

How the main result changes when **Tube size** changes and everything else stays at the example values above:

Tube size (mL)Days per tube5023753410045125571506820091

## Worked example

Inputs — Tube size: 100 mL; Amount per brushing (pea-sized portions): 2; Brushes per day: 2; People: 2; Wastage: 10 %; Price per tube: $4.

Results — Toothpaste used per day = 2.2 mL; **Days per tube = 45**; Tubes per year = 8; Cost per year = $32.14.

## FAQ

**How much toothpaste should I use?**
A pea-sized amount for children over three and adults; a smear the size of a rice grain for younger children.

**How long does a 100 mL tube last?**
For two people brushing twice a day with two pea-sized portions, about 45 days.

**Does more toothpaste clean better?**
No – brushing technique and fluoride matter, not the amount.

**What formula does the Toothpaste Calculator use?**
Use per day = people × brushes per day × amount per brush (pea-sized ≈ 0.25 mL) × (1 + waste).


## Sources

- [American Dental Association – Toothpaste](https://www.ada.org/)