Watch the full breakdown. The video walks through the build, the weight range, and a real-time load and unload.
An adjustable kettlebell is a single bell whose weight changes by adding or removing internal plates. One B.o.S. bell starts at 12 kg with the shell alone, reaches 20.5 kg on the five included plates, and climbs to 32 kg with the expansion pack, moving in 0.5 kg increments the whole way.
Kettlebells have a sneaky way of multiplying. One turns into three, three turns into a row of iron along the wall, and suddenly the home gym has less floor space than a phone booth.
An adjustable kettlebell collapses that entire rack into one bell. It saves space, and it saves a serious amount of money.
But not every adjustable bell is built the same way, and the differences show up fast under load. Here is how they work, what separates a good one from a frustrating one, and how to pick a starting weight.
What is an adjustable kettlebell?
An adjustable kettlebell is one bell that covers many weights. Instead of buying a separate bell for every load, you change the weight inside a single shell.
Plate-loaded designs do this with weight plates stacked in the core of the bell and held in place by hardware. Dial-based designs do it by locking onto a set of stacked plates in a cradle.
Either way the goal is the same: replace a shelf full of kettlebells with one piece of equipment that grows as you get stronger.
Are adjustable kettlebells worth it?
For most home gym owners, yes, and the math is the reason. Buying a full set of fixed bells means paying for six or seven pieces of iron and finding floor space for all of them.
One adjustable bell covers the same ground for one purchase and one footprint. That is the trade almost every garage gym and apartment setup ends up making.
The place adjustable bells lose people is build quality. A bell that rattles, shifts, or feels lopsided under a press gets abandoned, which makes the cheap option the expensive one.
How does a plate-loaded adjustable kettlebell work?
The shell is the body of the bell and the handle you actually grip. Plates sit inside it, stacked in the middle, and hardware holds them tight so nothing moves while you lift.
On the B.o.S. Adjustable Competition Kettlebell, a two nut system secures that stack from both sides. No matter how much weight sits in the middle, the load stays evenly distributed.
That is the detail that decides how the bell feels. Even distribution is why it handles like a fixed bell instead of something that tips back the moment it goes overhead.
The best adjustable kettlebell is the one you never have to buy twice. Bells of Steel
How much weight does one adjustable kettlebell cover?
A single bell covers a range rather than a number, and the range depends on what is loaded inside it.
| Setup | Weight range | Best for |
|---|---|---|
| Shell only | 12 kg | The lightest setting without accessories |
| Shell plus the five included plates | Up to 20.5 kg | Most beginners and general training |
| With the expansion pack | Up to 32 kg | Heavy swings, hinges, and carries |
| With the plastic bottom fitted | Starts at 9 kg | Lighter pressing and single-arm work |
Every plate you add or remove shifts the total in 0.5 kg steps, so the working weight is something you set exactly rather than round to.
Why do 0.5 kg jumps matter?
This is where fixed kettlebells quietly hold lifters back. Competition bells typically climb in 4 kg increments, so the next bell up is a big step.
That gap is why so many people stall. Going from a bell you can press cleanly to one that buries you is not progression, it is guesswork.
Progressive overload is the principle behind all of this. It means gradually increasing the demand on a muscle over time so it has a reason to keep adapting. Add load, reps, or difficulty in small steady steps, and strength follows.
The catch is the word gradual. A 4 kg jump is not a gradual increase for most lifters, which is why progress stalls at the exact moment the next bell is too heavy and the current one is too easy.
Half-kilo jumps keep that ladder intact. You add load at a pace your body can absorb rather than waiting weeks to earn a leap you are not ready for.
Plate-loaded or dial-style: what actually changes?
Speed is the honest advantage of dial designs. Turn a dial, pick up the bell, go. Plate-loaded bells take a little longer.
How much longer is worth being specific about, because the internet tends to exaggerate it. Changing the weight on this bell takes 30 to 90 seconds. That is a rest period, not an interruption, and it slots neatly between sets.
For that minute you get balance and durability that hold up under heavy loads. Most lifters find that a trade worth making.
| Factor | Plate-loaded (B.o.S.) | Typical dial designs |
|---|---|---|
| Changing weight | 30 to 90 seconds by hand, about the length of a rest period | Faster, usually a single dial turn |
| Balance | Two nut system keeps the load even at any weight | Can end up unbalanced or top-heavy |
| Materials | Steel shell with iron plates | Commonly plastic-bodied |
| Durability | Handles being dropped on concrete | Generally less durable over time |
If a bell only ever gets used for light work, speed might win. If it is going to see swings, drops, and years of use, the build matters more.
Do adjustable kettlebells feel like real kettlebells?
A good one does, and the specs are what make that true rather than marketing language.
This bell was built to match a competition kettlebell in the ways you actually notice. The window size is the same, and both share a 35 mm handle diameter.
Rack it and it sits in the same spot against your forearm. Press it overhead and the even weight distribution keeps it tracking properly rather than pulling backward.
How do you change the weight on an adjustable kettlebell?
Every bell ships with the tools needed to change weight, so there is no hunting through a drawer for the right wrench.
1. Remove the shell
Pull the outer shell off to expose the plate stack inside.
2. Take the nut off
Back the nut off so the plates are free to move.
3. Add or remove plates
Load the plates you want for the session. Each change moves the total in 0.5 kg steps.
4. Thread the nut back on and tighten
Seat the nut and snug it down with the tool so nothing shifts under load.
5. Refit the shell and finish
Put the shell back on and finish with the second tool. Give it a quick check before the first set.
Start to finish, the whole routine runs 30 to 90 seconds. Slower than spinning a dial, quick enough to do between sets, and the payoff is a bell that stays solid for years.
What size adjustable kettlebell should a beginner buy?
For most lifters, the 12 to 20.5 kg range is the right entry point. It covers swings, cleans, presses, and carries without being punishing on day one.
The expansion pack is always there later, so starting in the lighter range costs you nothing long term. You are not locking yourself into a ceiling.
If 12 kg is more than you want to begin with, the plastic bottom brings the starting weight down to 9 kg. That makes the same bell a sensible first kettlebell for lighter pressing and single-arm work.
Loading heavier is one way to progress, and it is not the only one. Adding reps, slowing the tempo, or moving to a harder variation all count. A bell that adjusts in small steps simply gives you more ways to keep moving forward.
Adjustable Competition Kettlebell
Steel shell, iron plates, and a two nut system that keeps the load balanced from 12 kg upward.
Shop Adjustable Kettlebell
12-32 KG Expansion Pack
Takes an existing 12 to 20.5 kg bell all the way to 32 kg. No second handle to get used to.
Shop Expansion Pack
Plastic Bottom
Drops the starting weight to 9 kg, opening the bell up to lighter pressing and single-arm work.
Shop Plastic BottomAdjustable kettlebell FAQ
What is an adjustable kettlebell?
One bell whose weight changes by adding or removing plates inside the shell, replacing the need for a full set of fixed bells.
Are adjustable kettlebells worth it?
For home gyms, usually yes. One bell costs less than a full set and takes up a fraction of the floor space, provided the build holds up to real training.
How heavy does an adjustable kettlebell go?
This one starts at 12 kg with the shell alone, reaches 20.5 kg on the included plates, and goes to 32 kg with the expansion pack.
Can you fit a lighter starting weight?
Yes. The plastic bottom brings the starting weight down to 9 kg instead of 12 kg.
Do adjustable kettlebells feel different from fixed ones?
A well-balanced one does not. This bell matches a competition kettlebell on window size and uses the same 35 mm handle diameter, so the rack and overhead positions feel the same.
Are adjustable kettlebells durable?
That depends entirely on materials. A steel shell with iron plates can be smashed on concrete and keep going, while plastic-bodied bells usually do not last as long.
How long does it take to change the weight?
Between 30 and 90 seconds, using the tools included with the bell. That fits inside a normal rest period, so it rarely interrupts a session.
What is progressive overload?
Gradually increasing the demand on a muscle over time so it keeps adapting. That can mean more weight, more reps, slower tempo, or a harder variation.
Why do plate-loaded bells adjust in 0.5 kg steps?
Because the plates are loaded individually. Fixed competition bells typically jump 4 kg at a time, which is where a lot of lifters stall out.
Is an adjustable kettlebell good for beginners?
It is one of the better first purchases. Small weight jumps suit early progression, and the range grows with you instead of needing replacing.
Still unsure which range to start with? The B.o.S. support team is happy to help you size it before you buy. Storage sorted too, with kettlebell storage and kettlebell accessories.
