Percent Yield Calculator
Calculate the percent yield of a chemical reaction from the actual and theoretical product amounts.
Must be greater than 0
Results
Percent Yield
70%
How to Use This Calculator
Enter your input values
Fill in all required input fields for the Percent Yield Calculator. Follow the units and input format printed next to each field. Where a unit selector is available, choose the units that match your data.
Review your inputs
Double-check that all values are correct and match the units or format shown for each field. Incorrect units are the most common source of calculation errors and can produce results that are off by factors of 2, 10, or more.
Read the results
The Percent Yield Calculator computes the output in your browser and displays the results, with units clearly labeled, as soon as they are ready — no data sent to a server.
Explore parameter sensitivity
Try adjusting individual input values to see how the output changes. This is a quick and effective way to develop intuition about how different parameters influence the result and to identify which inputs have the largest effect.
When to Use This Calculator
- •Use the Percent Yield Calculator when you need accurate results quickly without the risk of manual computation errors or unit conversion mistakes.
- •Use it to verify calculations made by hand or in spreadsheets — an independent check can catch errors before they lead to costly decisions.
- •Use it to explore how changing input parameters affects the output — a quick way to develop intuition and identify the most influential variables.
- •Use it when collaborating with others to ensure everyone is working from the same numbers and applying the same assumptions.
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About Percent Yield Calculator
The percent yield calculator compares the actual amount of product obtained in a chemical reaction to the theoretical maximum predicted by stoichiometry. Percent yield is a key performance metric in synthetic chemistry, pharmaceutical manufacturing, and industrial processes. A 100% yield means every atom of the limiting reagent was converted to product with no losses, which is virtually impossible in practice. Typical yields range from 50–90% for organic reactions and over 95% for some inorganic reactions. Factors reducing yield include incomplete reactions, side reactions, purification losses, and transfer losses. Understanding and optimizing percent yield is essential for economic and environmental efficiency.
The Math Behind It
Formula Reference
Percent Yield
% Yield = (actual / theoretical) × 100
Variables: actual = mass of product obtained; theoretical = maximum possible mass from stoichiometry
Worked Examples
Example 1: Aspirin synthesis
A student synthesizes aspirin and collects 3.5 g; the theoretical yield is 5.0 g.
The percent yield is 70%.
Common Mistakes & Tips
- !Not identifying the limiting reagent, leading to an incorrect theoretical yield.
- !Weighing wet product, which inflates the actual yield.
- !Getting >100% and not recognizing it as an error — product may be impure or not fully dried.
Related Concepts
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Frequently Asked Questions
What is a 'good' percent yield?
It depends on the reaction type. Above 90% is excellent for simple reactions. 70–90% is good for organic synthesis. Below 50% suggests significant side reactions or purification losses.
Can percent yield exceed 100%?
Not legitimately. A yield over 100% indicates experimental error — the product likely contains impurities, residual solvent, or an incorrect substance.
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