Comparing beauty products by price per bottle hides how far each one goes. A tiny bottle of liquid eyeliner can last months, while foundation is used up much faster. Most cosmetics also have a period-after-opening date (the open-jar symbol, e.g. 6M or 12M) – replace them after that even if some is left.
How to use the Beauty Products Calculator
- Product (typical applications per mL)
- Custom applications per mL
- Product volume
- Price
- Layers per application
- Applications per day
Results update as you type, and every field accepts the units shown in its menu.
How it works
Choose the product (or enter your own applications per mL), the volume, price, layers per application and how often you use it.
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
| Field | What to enter |
|---|---|
| Product (typical applications per mL) | Choose one: Mascara (≈ 40 per mL), Nail polish (≈ 10 per mL, both hands), Liquid lipstick (≈ 60 per mL), Foundation (≈ 2 per mL) … |
| Custom applications per mL | A number |
| Product volume | Units: mL, fl oz, L, US gal |
| Price | Amount in your currency |
| Layers per application | A number |
| Applications per day | A number |
What each result means
- Cost per application = [Price]÷[Total applications]
- Days it lasts = [Total applications]÷[Applications per day]
- Cost per year = [Cost per application]×[Applications per day]×365.25
Example values
How the main result changes when Custom applications per mL changes and everything else stays at the example values above:
| Custom applications per mL | Cost per application |
|---|---|
| 10 | 0.16 |
| 15 | 0.16 |
| 20 | 0.16 |
| 25 | 0.16 |
| 30 | 0.16 |
| 40 | 0.16 |
Formula
Applications = volume × applications per mL ÷ layers per useCost per application = price ÷ applicationsDays = applications ÷ uses per dayWorked example
Inputs — Product (typical applications per mL): Mascara (≈ 40 per mL); Custom applications per mL: 20; Product volume: 8 mL; Price: $25; Layers per application: 2; Applications per day: 1.
Results — Total applications = 160; Cost per application = $0.16; Days it lasts = 160; Cost per year = $57.07.
Frequently asked questions
How long does mascara last?
Most mascara should be replaced 3 months after opening for hygiene, even if some is left.
How many uses are in a bottle of nail polish?
A 15 mL bottle gives roughly 50–150 manicures, depending on coats.
How do I compare expensive and cheap products?
Compare the cost per application, not the bottle price.
What formula does the Beauty Products Calculator use?
Applications = volume × applications per mL ÷ layers per use.