The quick numbers: a 30 ml bottle holds about 150 pumps or roughly 600 drops. That is because one pump dispenses around 0.2 ml and one drop is about 0.05 ml (sources: deciemchatroom.com, oreateai.com, ~2026). Knowing this turns a vague “will this last?” into a real applications-per-bottle figure.
Pumps in a 30 ml bottle
At about 0.2 ml each, 30 ml works out to roughly 150 pumps. So a once-daily, one-pump routine lasts about five months on usage alone - though most people use more than a single pump, and PAO expiry may cut it shorter.
Drops in a 30 ml serum
At about 0.05 ml a drop, 30 ml is close to 600 drops. Serums are typically dosed at 2-4 drops per application, which is 150-300 uses from one bottle - hundreds of mornings before you need a refill.
Turn it into cost per use
Divide the price by total applications and you get cost per use. Plug your bottle size, price, and pumps or drops per use into the longevity calculator above to see the exact figure, plus whether the product expires before you can finish it.