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Toothpaste Calculator

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If you brush your teeth twice a day, every single day (and we hope you do), you'll definitely run out of toothpaste every couple of months tops. No one likes it when it's over, especially when you have no backup option in place. That's why we built this simple calculator to help you estimate the durability of your toothpaste. To get your result, you'll need to insert the following values:

  • Toothpaste capacity – The volume of the container, so how many milliliters/fluid ounces fit in a tube.

  • Wastage – The amount of toothpaste that stays inside the tube even though you're trying to squeeze it out so hard (sometimes it just won't work without cutting the thing open).

  • Pea sizes of toothpaste – 1 pea size is the recommended amount of toothpaste you should use with every wash. Don't trust those commercials that suggest at least triple this – most stomatologists agree one pea size is perfectly enough.

  • Daily brushes – How many times you brush your teeth every day (please say it's at least two).

  • People in the household – How many people do you share your toothpaste with?

  • Toothpaste price – How much does a single tube of toothpaste cost you?

That's it. The tool will instantly tell you how long the toothpaste will last, given the values you entered. Treat it as an approximate value, of course, but it should give you some general idea about the durability or the toothpaste and its cost.

And if you want to estimate the longevity and/or total costs of other aspects of your life, feel free to check out our other tools:


How much toothpaste do I need for a month?

An average person will need about 17.5 ml (0.6 fl oz) of toothpaste a month brushing twice daily with a pea-size portion.

To calculate exactly how much toothpaste you need for one month:

  1. Determine the number of persons using that toothpaste, daily brushes (per person), and the size of a single toothpaste portion (keeping in mind a pea-size is about 0.25 mL or 0.0085 fl oz).

  2. Use the following formula (30.5 is the average number of days a month):

    Toothpaste for a month = Daily brushes × Pea-sizes × Persons × 30.5

  3. You can multiply the amount by 1.1 to count in the wastage.

  4. You can always double-check with the Omni toothpaste calculator.

How do I calculate the best price for toothpaste?

To calculate the best price for toothpaste:

  1. To compare them, you need to find the best price for a fixed amount of toothpaste.

  2. Let's suppose you want to compare prices for one fl oz.

  3. To know the price for one fl oz, you need to know the capacity and the price of a toothpaste.

    Price for one fl oz = Price/Capacity (fl oz)

  4. Now, you can compare the prices of various toothpaste tubes and not worry about different packaging.

How long does a 4 oz tube of toothpaste last?

If you use it alone, brushing twice daily with a pea-sized portion, a 4 oz tube of toothpaste will last even seven months. For two persons using it the same way, it will last for 3.5 months. For a four-sized family, a 4 oz tube of toothpaste should do for seven weeks.

Does toothpaste expire?

Yes, toothpaste can expire. Most kinds of toothpaste have an expiration date of two years from the manufacture date.
Using it probably won't be dangerous, but it will also show no benefits. The fluoride in expired toothpaste won't be as effective in preventing cavities and cleaning your teeth. The taste can also go bad.

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