Free Barbell Plate Calculator
Your brain deserves a spotter too.
Figuring out which plates to load shouldn't require mental gymnastics between sets. Plate Math is a free barbell calculator that shows you the exact plates to put on each side — instantly. Enter a weight, see the plates. It handles the subtraction, the division, and the rounding so you can focus on lifting.
Open the Calculator →How a Barbell Calculator Works
Every barbell plate calculation follows the same core steps: take your target weight, subtract the bar, and divide what's left by two. That gives you the weight per side. A good calculator then figures out the best combination of available plates to hit that number. Plate Math does this automatically and shows you the result as color-coded plates — matching the IWF standard colors you'd see on competition bumper plates.
More Than Basic Math
A simple calculator stops at "45 + 25 per side." Plate Math goes further. You can set your actual plate inventory, so it only suggests plates you have. Switch between Full Bar and Half Bar mode for landmine and T-bar rows. Use Build mode to reverse the process — tap plates onto a virtual bar and see the total. There's also a percentage calculator for working out training percentages from a max.
Built for Real Training
Pro features include Session Prep for planning an entire workout's plate changes, Multi Lifter mode for sharing a bar between training partners, and Session Builder for programming complex training days. These tools save time and reduce the mental load of plate math during a session.
FAQ
How do I calculate plates for a barbell?
Subtract the bar weight (typically 45 lbs or 20 kg) from your target weight, then divide by 2. That gives you the weight needed per side. Then figure out which plate combination adds up to that number.
Is this barbell calculator free?
Yes. The core calculator, percentage tool, and Build mode are completely free with no sign-up required. Pro tools like Session Prep and Multi Lifter are available as an optional upgrade.