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Everyone has that drawer. Three serums with an inch left in the bottom, a cleanser you’re fairly sure you bought last spring, and no idea whether any of it is nearly finished or barely started.
So here’s the short version. A 10ml serum lasts about three weeks. A 100ml cleanser lasts about four months. A 30ml facial oil sits somewhere between two and four, depending on how heavy your hand is.
But those are averages, and you’re not average. What you actually want, standing at a checkout choosing between the small bottle and the big one, is the number for you. That takes about ten seconds of math and two pieces of information: how much comes out in one press, and how many presses you use a day.
The second one you already know. The first one is the problem, because hardly anyone tells you. So we counted ours.
Key takeaways
- Most pumps dispense 0.1ml to 0.2ml per press. Ours measure 0.117ml for serums and 0.175ml for cleansers.
- The formula: bottle size ÷ ml per press ÷ presses per day = days of use.
- Used twice daily, a 10ml serum lasts roughly 20 days, a 15ml about 30, a 30ml about 60.
- Cleansers stretch further than serums because the bottles are bigger, not because you use less.
- How long a bottle lasts and how long it stays good are two different clocks. Buying bigger isn’t always better value.
The formula
Take the bottle size in milliliters. Divide it by how much comes out in one press — that’s how many presses are in the bottle. Then divide by how many presses you use a day.
Bottle size ÷ ml per press ÷ presses per day = days
Our 15ml serums have a 0.117ml pump, so there are about 128 presses in a bottle. Two in the morning, two at night, and you’re through it in around 32 days.
That’s it. It only feels complicated because the middle number is usually missing.
How much actually comes out of one pump?
| Product | Size | Presses per bottle | ml per press |
|---|---|---|---|
| Aloe Herb & Citrus Mint Cleansers | 50ml | 285 | 0.175 |
| Aloe Herb & Citrus Mint Cleansers | 100ml | 570 | 0.175 |
| Phytonutrient Cleanser | 100ml | 570 | 0.175 |
| Serums | 15ml | 128 | 0.117 |
| Serums | 30ml | 230 | 0.130 |
| Facial Oils | 15ml | 115 | 0.130 |
| Anti-Aging Facial Oil | 30ml | 230 | 0.130 |
| Toning Mists | 50ml | 400 sprays | 0.125 |
| Coconut Body Oil & Radiant Skin Silk | 100ml | 608 | 0.164 |
| Coconut Body Oil & Radiant Skin Silk | 200ml | 203 | 0.985 |
The last two rows look wrong together and they aren’t. The 200ml body oil has a gooseneck dispenser instead of a fine pump, so one press gives you about six times what the 100ml gives you. You press it once where you’d press the small bottle five or six times. Same amount of oil ends up on your skin either way, which is the reason we list milliliters rather than leaving you to compare press counts that don’t mean the same thing.
How long does a serum last?
This is the one people worry about, because serums come in the smallest bottles and cost the most per milliliter.
At two presses, twice a day:
| Bottle | Once daily | Twice daily |
|---|---|---|
| 10ml | ~40 days | ~20 days |
| 15ml | ~60 days | ~30 days |
| 30ml | ~120 days | ~60 days |
| 50ml | ~200 days | ~100 days |
Our 15ml serums come out at 30 to 45 days in real use, which is about where the maths puts them.
The 30ml bottles—Anti-Aging Serum, Activated Night Serum, Activated Hemp Serum, Wild Fruit Serum—hold roughly 230 presses. Morning and night, that’s a little under two months. Once a day, closer to four.
If yours disappears faster than that, it’s almost always dose rather than frequency. A serum is a concentrate. Two presses covers a face.
See the Anti-Aging Serum in 15ml and 30ml.
How long does a 100ml face wash last?
Much longer than a serum, and only because the bottle is nearly seven times the size. You’re not being more careful with it.
At two presses twice a day, around 0.7ml a day:
| Bottle | Approximate life |
|---|---|
| 50ml | ~2 to 2.5 months |
| 100ml | ~4 to 5 months |
| 150ml | ~6 to 7 months |
| 200ml | ~9 months |
This is where the size question actually earns its keep. A 100ml cleanser costs less per month than a 50ml one and lasts twice as long, so if you know you’ll finish it, the bigger bottle is the better buy. Hold that thought, though — there’s a catch further down.
What about moisturizers, eye creams and body products?
These swing much more widely, because how much you need depends on how much skin you’re covering.
Moisturizer
Most people use half to one milliliter at a time. A 50ml jar gets you six to twelve weeks at twice daily. A 100ml bottle, three to five months.
Eye cream
The smallest dose in the whole routine. A grain of rice does both eyes, which is under 0.2ml. Our Anti-Aging Eye Cream runs two to three months if you’re using it once a day. Twice a day roughly halves that.
Body oil and lotion
Covering a whole body takes far more product than anything you put on your face. Our 100ml body oils last about two months with daily use, the 200ml about four.
Toning mist
A 50ml toning mist bottle holds around 400 sprays. Four sprays morning and night works out at two to three months.
Why did mine run out so much faster?
You’re using more than you think
This is the big one. Most people use about twice as much serum and oil as they need.
You’re not just doing your face
Neck and décolleté roughly double the area you’re covering, and the bottle doesn’t know you’ve added them.
There’s product below the dip tube
The last few milliliters sit under the straw and the pump can’t reach them. Unscrew the top and tip it out and you’ll usually get several more applications that would otherwise go in the bin.
It was a trial size
A 5ml trial serum used twice a day is a ten-day product. It was never going to see out the month.
How long it lasts vs. how long it stays good
Two different clocks, and they get mixed up constantly.
How long each bottle lasts depends on how quickly you use it — the arithmetic above tells you roughly when you’ll reach the bottom.
How long it stays good starts the day you open it. Natural and organic formulas generally have a shorter opened life than conventional ones, because the preservative systems are gentler. That’s part of what you’re choosing when you buy them.
Which brings back the catch from the cleanser section. Bigger isn’t automatically better value. If a 200ml bottle takes you nine months to get through and it’s good for six, you’re throwing the last third away. Now that you can work out your own usage rate, buy the size you’ll actually finish.
More on that second clock: do our products have expiration dates?
Work it out for your own routine
Check the size on the bottle. Use 0.12ml per press for a serum or facial oil and 0.175ml for a cleanser. Count what you actually use in a day.
Bottle size ÷ ml per press ÷ presses per day.
If it turns out you’ve been buying the wrong size for years, you’re in good company. Start with whichever bottle is closest to empty.
References
- U.S. Food and Drug Administration — Shelf Life and Expiration Dating of Cosmetics
- Regulation (EC) No 1223/2009 on cosmetic products — Period After Opening requirements
- Pump output measurements taken in-house by Annmarie Skin Care, 2026.
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