Beauty Calculators
Perfume sprays and cost.
Enter bottle size, price and how much one spray delivers. See how many sprays the bottle holds, what each ml, spray and wear costs, how long it lasts, and a fair price for a 5 ml or 10 ml decant. Compare a second bottle. Runs in your browser.
Bottle and habits
Sprays and cost
Fill the form and press Calculate.
Worked example
A 50 ml bottle costs $120 and one spray delivers 0.1 ml. That is 50 / 0.1 = 500 sprays. Cost per ml = $120 / 50 = $2.40, cost per spray = $0.24. At 4 sprays a wear you get 125 wears, so each wear costs $0.96, and at 5 wears a week the bottle lasts 175 days (25 weeks). A 5 ml decant at the same price per ml is worth $12.00.
How it works
sprays = (bottle ml - unusable ml) / ml per spray. Cost per ml = price / bottle ml. Cost per spray = price / sprays. Wears = sprays / sprays per wear. Days to finish = wears / wears per week x 7.
ml per spray is the number that moves everything. No standard sets it and atomizers vary, so the page defaults to a common-sense 0.1 ml that is an assumption, not a measurement. To measure yours, spray 10 times and divide the grams lost by 10, then by the liquid's density (default 0.85 g/ml, also an assumption).
The decant line is price per ml times 5 or 10 and ignores vial, atomizer and labour, so it is the break-even price of the liquid only.
Sources and basis (checked 2026-10-04): all inputs are yours. Reference point for the density default: ethanol density 0.789 g/mL at 20 C, NIH PubChem, Ethanol.
FAQ
How many sprays are in a perfume bottle?
Usable ml divided by ml per spray. At 0.1 ml a spray a 30 ml bottle gives about 300 sprays, 50 ml about 500 and 100 ml about 1,000. If your atomizer delivers 0.07 ml, the same 50 ml gives about 714.
How do I measure ml per spray?
Put a small cloth on a kitchen scale, spray 10 times into it and note the grams gained, or weigh the bottle before and after. Divide by 10 for grams per spray, then divide by the density (about 0.85 g/ml is a fair starting guess) to get ml.
How is cost per ml different from cost per wear?
Cost per ml compares bottles of different sizes. Cost per wear says what each day of wearing it costs, which depends on how many sprays you use.
How long will a bottle last?
Wears per bottle divided by wears per week gives weeks. At 4 sprays a wear and 5 wears a week, a 50 ml bottle at 0.1 ml per spray lasts about 25 weeks. Fragrances are best used within the shelf life on the pack.
What is a fair price for a decant?
The break-even for the liquid is price per ml times the decant size. Sellers add the vial, atomizer, labour and risk, so expect to pay more.