A percent yield calculator compares how much product you actually made in a chemistry experiment with how much you could have made in theory. Enter the actual yield and the theoretical yield, and it calculates the percent yield, a key measure of how efficient a reaction or lab procedure was.
The formula is: percent yield = (actual yield ÷ theoretical yield) × 100. For example, if stoichiometry says a reaction should produce 12.5 g of product and you recover 10.8 g, the percent yield is 10.8 ÷ 12.5 × 100 = 86.4 percent. To find the theoretical yield, use a balanced equation, convert the limiting reactant to moles, apply the mole ratio and convert to grams of product.
Why is percent yield usually below 100 percent? Reactions may not go to completion, side reactions can form unwanted products, and some product is lost during filtering, transferring or purifying. A yield above 100 percent usually signals an error, such as a product that’s still wet or contaminated with impurities.
Tips: always identify the limiting reactant first, keep units consistent, and dry products thoroughly before weighing. In lab reports, explain possible sources of error and how they would affect the yield. Use the correct number of significant figures based on your measurements.
Why use an online Percent Yield Calculator: it saves time, avoids simple arithmetic mistakes and shows each step, so you can check your homework, plan a project or make a decision with confidence. Bookmark the page so it’s ready the next time you need it.
Tips for getting accurate results from the Percent Yield Calculator: double-check that every input uses the right units, enter numbers without commas or symbols, and run the calculation a second time with a quick estimate in your head to confirm the answer looks reasonable.
Learn more on Wikipedia’s chemical yield article. Find stoichiometry, balancing equations and pH calculators on Minedit.