Theoretical Yield Calculator
Last updated: June 2026 · Free · No sign-up required
Enter values above and click Calculate to see your result instantly.
Quick reference
| Step | What you need |
|---|---|
| Balanced equation | Correct mole ratios |
| Moles of reactant | mass / molar mass |
| Limiting reactant | Runs out first |
| Mole ratio | Product moles per reactant mole |
| Product mass | moles × molar mass |
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Below the calculator we link a small set of plain-English explainer pages — "What is a percentage?", "Why does PEMDAS matter?", and so on. They cover the underlying concept in 4–6 short paragraphs. Read those before the calculator if the topic is new, or after if you want the extra context.
Interpretation guide
| Result | Meaning |
|---|---|
| Theoretical yield | Max product if 100% efficient |
| Actual yield | What you really recover |
| Percent yield | actual / theoretical × 100 |
| > 100% yield | Impurities or measurement error |
Formula & methodology
Formula: Theoretical yield = moles of limiting reactant × mole ratio × molar mass of product
How the result is calculated
Theoretical yield is the most product a reaction can make if every bit of the limiting reactant converts perfectly. You convert the limiting reactant to moles, scale by the balanced mole ratio, then convert product moles back to mass.
- Balance the equation and convert each reactant’s mass to moles (mass ÷ molar mass).
- Find the limiting reactant — the one that produces the least product.
- Multiply its moles by the product:reactant mole ratio, then by the product’s molar mass.
Example
4.0 g H₂ (2.0 mol) with excess O₂ forming H₂O (ratio 2:2): 2.0 mol H₂O × 18.02 g/mol = 36.0 g theoretical yield of water.