Estimate how many doses a serum bottle gives and its cost.
Multiplying bottle volume by drops per millilitre gives total drops, which divided by the dose gives how many uses a bottle lasts. Used daily, a serum is a recurring cost, so the drops-per-bottle math turns a single price into a per-day habit cost.
Serum Drops per Bottle
Uses per bottle = bottle volume x drops per mL / drops per use
Uses per bottle = bottle volume x drops per mL / drops per use Multiplying bottle volume by drops per millilitre gives total drops, which divided by the dose gives how many uses a bottle lasts.
Used daily, a serum is a recurring cost, so the drops-per-bottle math turns a single price into a per-day habit cost.
This calculator takes 4 inputs: Bottle volume, Drops per mL, Drops per use, Serum price. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.