Calculator
Skincare unit-price calculator
Compare two or three packages using the same unit. Enter the price you want to compare, including tax or shipping only if you apply the same approach to each option. We do not look up live prices.
Results
Results appear here after you press Calculate. Nothing you enter leaves this page.
Input rules
- Option label: optional plain text up to 60 characters; never sent or saved. Default A/B/C.
- Price: USD, 0.01-10,000; at most two decimal places.
- Quantity: 0.01-10,000, up to two decimals.
- Unit: mL or g. All compared options must have the same unit.
- Comparison: two rows required; third optional. Remove-row clears its values.
Worked examples
Each example is worked through step by step, so you can check the arithmetic.
Two packages in mL
- $12/120mL = $0.1000/mL and $10.00/100mL
- $18/200mL = $0.0900/mL and $9.00/100mL
- First option is 11.11% higher per unit than the second.
A tie in grams
- $10/100g = $0.1000/g
- $20/200g = $0.1000/g
- Unrounded costs differ by less than 0.000001, so the result is a tie.
Mixed units
- One option in g and one in mL
- Blocked with “Choose the same unit for every option.”
Entries that block a result
- Zero quantity, blank required values, NaN and negatives block results.
- No result is shown until Calculate is pressed with valid entries.
Next step
Estimate replacement spending
Turn a package price and your own replacement interval into annual, monthly and upfront figures.