Mass Percent Calculator (% w/w)
Mass percent calculator: percentage by mass of a solute in a solution, or the masses needed for a target %.
w = msolutemsolution × 100
How to use this calculator
- Choose the quantity you want under “Solve for”.
- Type the known values and pick their units: any combination works.
- The result updates as you type. Open “Show the steps” to see the substitution.
w = m(solute)/m(solution) × 100. The solution mass includes solute plus solvent.
Formula
w = msolutemsolution × 100
| Symbol | Quantity | Units |
|---|---|---|
| ms | Mass of solute | kg, g, mg, µg, t, lb, oz, st, US ton, ct, Da |
| m | Mass of solution | kg, g, mg, µg, t, lb, oz, st, US ton, ct, Da |
| w | Mass percent | %, × |
Worked example
Given: ms = 10 g · m = 250 g
w = msm
Result: w = 4 %
Frequently asked questions
10 g of salt in 250 g of solution?
4 % w/w, with 240 g of water.