How to Switch Workout Weights From kg to lb Without Losing Your Log

To switch workout weights from kg to lb, choose one display unit for your log, convert a few familiar working weights once, and keep the exercise and set details the same. Do not rewrite every old session by hand. A consistent display makes it easier to compare like with like, whether your gym plates, training partner, or new programme use a different unit.

Use this quick checklist:

[ ] Pick the unit I will use for my next training block: kg or lb.
[ ] Convert only the working weights I use often.
[ ] Round to the plates that actually exist at my gym.
[ ] Keep the exercise name, sets, and reps unchanged.
[ ] Add a short note only if a machine or bar has an unusual starting weight.

For a precise reference, 1 lb equals 0.45359237 kg, and 1 kg equals about 2.20462 lb. Those are unit conversions, not strength equivalents. A 100 lb machine at one gym is not necessarily comparable with a 100 lb machine at another gym because equipment can have different mechanics and starting resistance. NIST's conversion guidance is a sound reference for the units themselves.

How do you switch workout weights from kg to lb?

Start with the loads you genuinely use. Multiply kilograms by 2.20462 for an approximate pound value, then choose the load you can actually set on the machine, dumbbell rack, or bar. For the reverse direction, multiply pounds by 0.45359237.

Here are useful gym-log references rounded to one decimal place:

The point is not to chase extra decimals. If your dumbbells jump from 20 kg to 22 kg, record the weight you actually lifted. If a selectorised machine has a 45 lb pin but no 44 lb option, record 45 lb and keep that machine's name consistent in your log.

A worked gym-log example

Suppose your old entry says:

Incline dumbbell press
3 sets × 8 reps × 20 kg per dumbbell

Twenty kilograms is about 44.1 lb, but your new gym has 45 lb dumbbells. Your new entry can be:

Incline dumbbell press
3 sets × 8 reps × 45 lb per dumbbell

That is a practical display change, not proof that the two sessions are identical. Keep the exercise, repetitions, and any relevant equipment note clear. If you need to compare the sessions later, you can see that 20 kg and 45 lb are close enough to explain the switch without pretending the equipment or execution was exactly the same.

What should stay the same when you change units?

Changing units should make a record easier to read, not turn it into a new training plan. Keep these details stable whenever they still describe the same movement:

• Exercise variation: Do not merge two different machines just because the displayed load matches.
• Sets and reps: They give the load useful session context.
• The actual load: Record what was on the bar, pin, or dumbbell handle, after any rounding needed for the equipment available.
• A short equipment note: Use one when a plate-loaded machine, assisted machine, or non-standard bar makes the number ambiguous.

If the equipment changes enough that the history stops being useful, treat it as a distinct exercise variation. That is more honest than forcing two unlike setups into one line just to preserve a chart.

A PeakBFF workflow for kg and lb workout logging

PeakBFF keeps workout set weights in kilograms internally, then formats the display in kg or lb at the app boundary. Its Weight unit setting lets you choose metric or imperial, and the same preference is used across weight, height, and distance displays. Switching the preference changes how the record is shown. It does not require you to recreate completed sets in a second unit.

Use it like this:

1. Open your settings and select Weight unit.
2. Choose Metric for kg or Imperial for lb.
3. Start your normal workout and enter the load you actually use in the selected display unit.
4. Keep a distinct exercise name when a new machine has a meaningfully different setup.
5. Review the completed session with its sets and reps still attached to the exercise.

The useful boundary is simple: a display preference can remove mental conversion while you log, but it cannot make mismatched gym equipment equal or decide what load you should use. For a separate practical tool when the question is loading a bar rather than converting your log, use our barbell plate-loading template.

When should you keep both kg and lb in a note?

Usually, you do not need both units in every row. One display unit is cleaner. Use a one-time note or this small transition worksheet if you train across two gyms or inherit a programme written in the other unit:

EXERCISE:
Old display:              kg / lb
Old working load:
Converted reference:
Available load at this gym:
New display:              kg / lb
Equipment or setup note:

Fill it in only for the lifts that matter to your routine. The worksheet is a reference for the transition, not a rule that every session has to hit an identical converted number.

The bottom line

The best way to switch workout weights from kg to lb is to choose one display unit, convert familiar loads once, and log the equipment you actually use. Keep the movement, sets, reps, and any useful setup context intact so future comparisons still mean something.

PeakBFF is a straightforward option if you want that unit preference beside a normal gym log, plus food and nutrition records in the same app. If connected health records are also part of your setup, see our gym-and-nutrition Apple Health comparison. Download PeakBFF on the App Store or Google Play.