A unit conversion describes the same mass. It does not create an exact match between different plate sets.
Use the conversion factor
To convert pounds to kilograms, multiply by 0.45359237. To convert kilograms to pounds, divide by that same number. IronMath Fitness rounds the displayed conversion to one decimal place.
Familiar numbers, different systems
| Weight | Converted value |
|---|---|
| 45 lb | 20.4 kg |
| 135 lb | 61.2 kg |
| 225 lb | 102.1 kg |
| 100 kg | 220.5 lb |
A converted number is not always loadable
225 lb converts to about 102.1 kg. If your kg setup uses a 20 kg bar and you can only change the total in 2.5 kg steps, 102.1 kg is not a weight you can assemble exactly. Use the plate tool to check your options.
A 20 kg bar and a 45 lb bar are also not precisely equal. Keep the actual bar weight in your calculations instead of replacing one with the other by habit.
Keep a consistent training log
- Record the unit next to every weight.
- Include the bar in your totals consistently.
- Use the converter when comparing sessions in different gyms.
- Log the load actually used after plate rounding.
Avoid rounding every intermediate step
For a percentage-based plan, calculate in the unit you will load whenever possible. Convert the final result if needed. Repeatedly rounding converted values can introduce small differences that look more precise than they are.
Check your own numbers.
Sources & approach
This guide combines linked references with IronMath Fitness examples. It provides general information, not a personal training plan.