Percent Solution Calculator
Work out a percent (weight/volume) concentration, or how much solute you need for a target percentage. Enter any two values and leave the one you want to find blank.
Leave exactly one field blank to solve for it.
How it works
A weight/volume percentage, %(w/v), is the number of grams of solute in 100 mL of solution: %(w/v) = mass in grams ÷ volume in mL × 100. It is the most common way to express the concentration of a solid dissolved in a liquid, for example a 0.9% saline solution is 0.9 g of NaCl in 100 mL.
Enter any two of mass, volume and percent and leave the third blank — the calculator rearranges the formula and solves it. Mass units (g, mg, µg) and volume units (mL, L, µL) can be mixed freely; the answer is returned in the unit you selected for the blank field.
The same part-over-whole arithmetic gives weight/weight %(w/w) — grams of solute per 100 g of solution — and volume/volume %(v/v) — mL of solute per 100 mL of solution — when both quantities share the same unit.
Examples
- 5 g of glucose in 100 mL: %(w/v) = 5 / 100 × 100 = 5%.
- Physiological saline: 0.9% w/v means 0.9 g of NaCl in 100 mL.
- For 250 mL of a 2% solution: mass = 2% × 250 mL / 100 = 5 g of solute.
Frequently asked questions
- What does percent (w/v) mean?
- Weight/volume percent is the grams of solute dissolved in 100 mL of total solution. A 1% w/v solution contains 1 g of solute per 100 mL.
- How is w/v different from w/w and v/v?
- w/v is grams per 100 mL, w/w is grams per 100 g, and v/v is millilitres per 100 mL. This calculator computes w/v; the same part-over-whole arithmetic applies to w/w and v/v when the two amounts use the same unit.
- Can I mix units?
- Yes. Pick any mass unit (g, mg, µg) and volume unit (mL, L, µL); conversions are handled internally and the result is shown in the unit you chose for the blank field.
- How do I convert percent to molarity?
- Divide the grams per litre (10 × the w/v percent) by the molecular weight. For example 5% w/v is 50 g/L; for a compound of MW 100 g/mol that is 0.5 M.