How to calculate skincare price per ml and per ounce

The two formulas

Price per ml is the price divided by the size in milliliters. Price per fluid ounce is the price divided by the size in US fluid ounces. Since 1 US fl oz is 29.5735 ml, you can switch between them by multiplying or dividing by 29.57.

• Price per ml = price / ml
• Price per fl oz = price / fl oz
• Price per fl oz = price per ml x 29.57
• ml = fl oz x 29.57
• fl oz = ml / 29.57

Open the price per ml calculator →

Step by step with a calculator

Our price per ml calculator does this for up to three products at once and highlights the lowest. It accepts ml or fl oz.

1. 1

   Find the size on the listing or carton. Use ml if it is given; it is usually the more precise number.

2. 2

   If only ounces are given, multiply by 29.57 to get ml.

3. 3

   Divide the price by the ml. Round to two decimals.

4. 4

   Repeat for each product you are comparing.

5. 5

   Compare the price per ml numbers. The lowest is the cheapest per unit.

6. 6

   If you want per ounce, multiply each price per ml by 29.57.

Worked examples from real listings

These use the listed prices at the time of writing. Prices change, so rerun the numbers before you buy.

Note.Price per ml compares cost per unit, not how much you will use. A watery essence used in larger amounts can cost more per day than a cream with a higher price per ml.

Converting ml and ounces correctly

Labels round ounces. A 50 ml jar is usually printed as 1.7 fl oz or 1.69 fl oz, and a 30 ml bottle as 1 fl oz or 1.01 fl oz. When both are on the label, use the ml figure. If you divide by the rounded ounce figure instead, you get slightly different results; for example, SK-II's 7.7 oz gives $31.82 per oz while 230 ml gives $31.50 per fl oz. Small gaps like this come from rounding, not from a different product.

Our skincare size chart lists the common sizes in both units, and the figure below shows them side by side.

Comparing sizes, refills and sets

Bigger jars and refills often cost less per ml. Augustinus Bader The Cream is $6.30 per ml in 50 ml and $5.65 per ml in 100 ml. Lancome Absolue The Rich Cream costs $280.00 in the jar and $242.00 as a 2.0 oz refill, which is about $4.09 per ml for the refill. Our refills explained page covers how refill pods work.

Sets are harder. To get a fair number, add up the ml of only the items you will use and divide the set price by that. If a set has items you will not use, they add nothing to the value. Our mini vs full size page and the gift sets guide go further. For a ready-made comparison of creams, see the face cream price per ml chart.

Common mistakes

Price per ml is only one part of value. Texture, how much you use and whether the product suits your skin matter too. Patch test any new product, and ask a dermatologist if you have a skin condition. The luxury face cream guide lists price per ml for every jar it covers.

• Comparing a 30 ml price with a 50 ml price without dividing.
• Mixing fl oz and weight oz. Creams in the US are often labeled in fl oz, but some list net weight in oz; check which one the label uses.
• Forgetting that a refill needs the original jar.
• Counting the stated value of a set rather than its actual price.
• Buying a large size you will not finish within the period after opening on the box.

Frequently asked questions

What is 1 fl oz in ml? 1 US fluid ounce is 29.5735 ml. Most people round it to 29.57 or 30 for quick math.

Is price per ml or per ounce better? Either works as long as you use the same unit for every product. Price per ml is easier when labels give ml.

Why do my numbers differ slightly from a store's unit price? Usually rounding of the ounce size. Use the ml figure for the most consistent result.

Does a lower price per ml always mean better value? No. It means cheaper per unit. Value also depends on how much you use per day and whether you finish it in time.