What is the Percent Yield Calculator?
Percent yield compares how much product you actually isolated to the maximum possible from stoichiometry. The formula is % yield = (actual yield / theoretical yield) × 100. Enter any two of percent yield, actual yield, and theoretical yield and this calculator solves the third. Use grams or moles — as long as both yields share the same unit. Also shows the unrecovered amount. Runs instantly in your browser with no signup.
How to use the Percent Yield Calculator
- Choose what to solve: percent yield, actual yield, or theoretical yield.
- Enter the two known values.
- Select grams (g) or moles (mol) for both yields.
- Read the solved value and unrecovered amount.
- Copy the summary for your lab report.
Common use cases
- Finding % yield after isolating 4.2 g product from 5.0 g theoretical
- Estimating actual yield when a reaction typically gives 75%
- Back-calculating theoretical yield from 3 g product at 60% yield
Frequently asked questions
- What is percent yield?
- % yield = (actual yield / theoretical yield) × 100. It measures reaction efficiency — how much product you obtained versus the stoichiometric maximum.
- What is theoretical yield?
- Theoretical yield is the maximum product mass or moles predicted from the balanced equation and limiting reactant. Calculate it with stoichiometry before using this tool.
- Can percent yield exceed 100%?
- Sometimes measured values exceed 100% due to impure product, solvent not fully removed, or weighing errors. The calculator will flag yields above 100%.
- Should I use grams or moles?
- Either works — use the same unit for actual and theoretical yield. Grams are typical for isolated solid product; moles are useful when comparing across reactions.
