Dumbbell pair calculator

Enter the spinlock handle weight and the plates on each end to see what each dumbbell and the pair weigh.

Your details

Each dumbbell

22.5 kg

a pair is 45 kg (99 lb)

Each dumbbell in pounds49.6 lb
Plates per dumbbell6
Plates for the pair12
Smallest jump from here2.5 kg a dumbbell (a 1.25 kg plate each end), 11.1% heavier
For 15 kg each, load each end with1 x 5 kg + 1 x 1.25 kg (4 plates a dumbbell)

A 2.5 kg jump is more than 10% at this weight, so add reps first (for example 8 to 12) before adding plates. Spinlock handles are often 2 to 2.5 kg, but weigh yours: cheap sets vary. Load both ends the same and check the collars are tight before every set.

Sharp pain, a pop, or pain that lingers after a session is a reason to stop and see a GP or physio. Chest pain or feeling faint while lifting: stop, and call 999 if it does not pass.

The working

Two 2.5s and a 5 each end

Each end holds 2.5 + 2.5 + 5 = 10 kg, so each dumbbell is 2.5 + 10 + 10 = 22.5 kg. The pair is 45 kg, about 99 lb, using 6 plates per dumbbell.

Working back from a target: 15 kg each on a 2.5 kg handle needs (15 − 2.5) ÷ 2 = 6.25 kg each end, which is 5 + 1.25. If a weight cannot be made exactly, the page gives the nearest either side: 14 kg needs 5.75 kg an end, so the choice is 12.5 kg or 15 kg.

The smallest jump on a spinlock set is one 1.25 kg plate each end, 2.5 kg a dumbbell. At 22.5 kg that is 11% heavier, so it often works better to add reps first, for example from 8 up to 12, then add the plates and drop back to 8. This is the double progression method.

Your plates

What your set can make

Add how many of each plate you own and we list every pair you can load, with four of each plate needed for a matching pair (one per end). With a 2.5 kg handle, four 1.25s, eight 2.5s and four 5s make 10 weights from 2.5 to 25 kg each, in 2.5 kg steps.

Add the reps you can do now and we estimate your one rep max with the Brzycki formula (weight × 36 ÷ (37 − reps)) and the reps to expect at the next 2.5 kg jump. 12 reps at 22.5 kg gives 32.4 kg, and at 25 kg about 9 reps, a sensible place to start the next round of double progression.

Home sets

Making the most of a few plates

Change sides with the same plates to save time
Use one dumbbell for goblet squats
Slow the lowering to make light weights harder
Add reps before adding plates

Safety

Collars and floors

Spin the collars tight before every set; loose plates are the commonest home gym mishap. A cheap mat saves the floor and your toes.

Read with care

What this cannot tell you

Uneven endsIt assumes both ends match.
Collar weightHeavy collars add a little; weigh one.
Fixed dumbbellsFixed dumbbells just show their weight.

Questions

Common questions

How heavy is a spinlock handle?

Usually 2 to 2.5 kg; weigh yours.

What dumbbells should a beginner buy?

An adjustable pair going up to about 15 to 20 kg each covers most moves.

Is a 20 kg pair 20 kg each?

Shops vary. Some mean 10 kg each; check the listing.

Sources

Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.

Before you push on

New to exercise, or got a heart, lung or joint condition? Have a word with your GP or practice nurse first. Stop and get help if you feel chest pain, faintness or unusual breathlessness, and call 999 if it is severe.