Relative Strength Comparison

Instructions

Enter two body weights and two corresponding weights lifted to find out which lift and/or lifter is relatively stronger. All weights entered should be in the same unit of measurement. The stronger score will be highlighted and the % Difference is how much stronger or weaker 1 is compared to 2.

What's relative strength and why am I comparing it?

Relative strength is how strong someone is in relation to their body weight. Absolute strength is simply how strong someone is regardless of body weight. Let's say there's a 200lb person who can bench 200lbs and a 120lb person who can bench 180lbs. In this case the 200lb person is absolutely stronger, but the 120lb person is relatively stronger.

Relative strength is useful for comparisons because it factors out body weight, allowing two people of different body weights to meaningfully compare themselves. It's also useful if you want to compare to yourself at a different weight. If you've gained or lost weight, comparing your relative strength is more useful than your absolute strength.

How does this calculator work?

This calculator is based on the concept of allometric scaling. Essentially, as body weight increases, strength does too, but just not as quickly. So someone who weighs 10% more is not expected to be 10% stronger. That means that the commonly used strength to body weight ratios are largely inaccurate for comparing relative strength. A 200lb person with a 1xBW bench is relatively stronger than a 120lb person with a 1xBW bench even though their ratios are the same. For a more in depth explanation of allometric scaling and relative strength, check out this this article by Greg Nuckols.