Adjustable Dumbbells: Are They Worth It?

For most people training at home, adjustable dumbbells are worth it. One set replaces a whole rack of fixed weights, fits in a corner of a flat, and lets you keep adding load as you get stronger. They're less worth it if you switch weights every few seconds, share kit with someone who lifts very differently, or need more weight than a set can hold.

What are adjustable dumbbells?

An adjustable dumbbell is a dumbbell whose weight you can change. Instead of buying a separate pair for 5kg, 7.5kg, 10kg and so on, you buy one set and load or unload weight plates to suit each exercise.

There are three main designs on the UK market:

To be upfront: the adjustable sets we sell at Hackerprice® are spin-lock and convertible plate-loaded designs. We don't currently stock dial or pin-select dumbbells, so if fast weight changes matter most to you, you'll need to look elsewhere for those.

How do spin-lock adjustable dumbbells work?

A spin-lock handle is a short threaded bar. The collars screw along the thread and clamp the plates in place. Changing the weight looks like this:

1. Rest the dumbbell on the floor or a mat, never on your lap.
2. Unscrew the collar from one end and slide off or add plates.
3. Do the same on the other end, so both sides match.
4. Screw the collars back on until they're tight against the plates.
5. Give the plates a firm twist by hand. If anything moves, tighten again before you lift.

Many sets also include a connecting bar, so the same plates can be used as a barbell. Our 25kg 2-in-1 dumbbell and barbell set works this way. Its 12 plates come in 1.5kg, 2kg and 2.5kg sizes, which gives you small jumps between weights.

Are adjustable dumbbells worth it? The case for

They save a lot of space

A full run of fixed dumbbells needs a rack, and a rack needs a wall. A spin-lock set, with its plates stacked, fits in a box under a bed or in a cupboard. For a flat or a spare room that also has to be a guest room, that's usually what decides it.

They cover a wide range of weights for one price

The price gap is easy to see in our own range. At the time of writing, a pair of 10kg rubber hex dumbbells costs about £61 and gives you one weight. For around £85, a 30kg adjustable set gives you many weights from the same plates. The more different weights you need, the more an adjustable set saves. Prices change, so check the product page before you buy.

They make steady progress easy

Getting stronger means slowly asking your muscles to do more, often by adding a little weight. With small plates you can move up in small steps, rather than jumping between whatever fixed pairs you happen to own.

They cover the whole body

The NHS physical activity guidelines recommend strengthening activities that work all the major muscle groups (legs, hips, back, abdomen, chest, shoulders and arms) on at least 2 days a week, and list lifting weights as one way to do it. A set of dumbbells you can make light for shoulder raises and heavy for squats covers that on its own.

The downsides of adjustable dumbbells

• Changing weight takes time. With a spin-lock set, plan on a minute or so per change. That's fine for straight sets with rest in between, but slow for circuits or drop sets.
• The handles are longer. A loaded spin-lock dumbbell is wider than a fixed one of the same weight. For example, the dumbbell bar in our 30kg 6-in-1 set is 50cm long. This can feel awkward on moves like chest presses, where the ends of the dumbbells meet.
• Collars need checking. Screw collars can work loose during a session, so get into the habit of checking them between sets.
• There's a ceiling. Once you're lifting everything the set holds, you'll need more plates or a different setup.
• Sharing is fiddly. If two people train together at different weights, one of you will be changing plates all the time.

Adjustable vs fixed dumbbells: side by side

In short: adjustable dumbbells are worth it if you train at home, have limited space and want to keep increasing the weight over months. Fixed dumbbells make more sense if you only need one or two weights, train in fast circuits, or share equipment with people who lift at very different weights.

Are adjustable dumbbells good for beginners?

Yes, and beginners arguably get the most from them. When you're starting out, the weight you can manage changes from exercise to exercise and week to week. A set that goes from light to heavy means you won't outgrow your kit in the first few months.

Two things help beginners in particular. Pick a set with small plates, so the steps between weights are gentle. And learn to change plates properly from day one: both ends loaded the same, collars tight. If you're new to exercise or have a health condition, the NHS advises speaking to a GP before starting.

How much weight should you buy?

This is where most people get caught out. The number on the box is the total weight of the whole set, including the handles. A "25kg set" does not mean two 25kg dumbbells. It means 25kg shared between two handles (and, with a 2-in-1 set, the barbell as well), so the most you can load onto one dumbbell is roughly half that, or less.

A practical way to decide:

1. Think about your heaviest movement, which is usually a squat, a lunge or a row.
2. Estimate how much you'd want in each hand for that movement, now and in six months.
3. Double it and add a little for the handles. That's roughly the set size to look for.

If you're unsure, buying slightly bigger than you need today usually works out cheaper than buying twice. You can always leave plates off.

Home gym considerations

• Floor protection: a rubber mat or exercise mat protects floors and makes changing plates on the floor easier. Plastic-coated plates are gentler on floors than bare metal.
• Space around you: give yourself room to press and row without hitting furniture. The longer handles of spin-lock dumbbells need a bit more clearance.
• Storage: keep plates stacked flat and low down, never on a high shelf.
• What comes next: dumbbells are the natural first buy. If you're planning the rest of the setup, our guide to building a home gym under £300 sets out what to add, and in what order.

Checklist before you buy adjustable dumbbells

• Is the total set weight enough, given that it's split between two handles?
• What plate sizes are included? Smaller plates mean smaller jumps.
• How do the collars lock? Screw-on spin-lock collars are the most common.
• How long is the handle once loaded, and will that suit your exercises?
• Does it convert to a barbell or kettlebell, and will you actually use that?
• Are the plates coated to protect your floor?
• Where will you store it between sessions?

Frequently asked questions

Are adjustable dumbbells good for beginners?

Yes. A beginner's strength changes quickly and differs between exercises, and an adjustable set lets you match the weight to each movement and add load gradually. Choose a set with small plates for gentle steps, and always check the collars are tight before lifting.

Are adjustable dumbbells better than fixed dumbbells?

Neither is better for everyone. Adjustable dumbbells save space and money when you need many weights. Fixed dumbbells are faster to switch between and simpler if you only use one or two weights. For most home gyms with limited space, adjustable sets are the more practical choice.

How much weight should I buy?

Remember the advertised figure is the total for the whole set. Work out how much you'd want in each hand for your heaviest exercise, double it and add a little for the handles. If you're between sizes, the larger set usually gives you more time before you need to upgrade.

How long does it take to change the weight on spin-lock dumbbells?

Allow a minute or so per change once you're used to it, as you unscrew each collar, swap plates on both ends and tighten up again. That suits straight sets with rest between them. If you want instant changes for circuits, fixed pairs or dial-type dumbbells are quicker.

Is a 25kg adjustable dumbbell set enough?

For many beginners and people training for general fitness, yes, at least to start with. Remember that 25kg is split across two handles, so each dumbbell holds roughly half of that or less. If you already lift heavier on squats or rows, look at a larger set.

The verdict

If you're training at home, short on space and planning to keep at it, adjustable dumbbells are one of the most useful things you can buy. Choose a set big enough to grow into, check the collars every session, and accept that plate changes take a moment. You can compare adjustable sets and fixed pairs in our dumbbells collection. Delivery is free across the UK, and you have 30 days to change your mind.

Written and checked by the Hackerprice® editorial team. Product details and prices were checked against our live catalogue when this guide was written and are reviewed regularly. Exercise guidance is taken from the NHS. Last updated: 23 September 2026.