A StepMill is a type of stair climber, not an alternative to one. "Stair climber" is the broad name people use for any exercise machine that simulates climbing stairs. Within that group, StairMaster builds two different mechanisms: StepMills (the 4G, 8Gx and 10G, sold as the Gauntlet range) carry a revolving staircase with real steps, and the 8 Series FreeClimber uses two independent stepping pedals instead.
So when you meet the words StepMill, stair climber, stair stepper, Gauntlet and FreeClimber, the question worth asking is not which category a machine belongs to. It is which mechanism it uses: a moving staircase you climb, or pedals you press down. That choice decides how the climb feels, how kind it is to your knees, how much headroom you need and whether you need a socket.
Key takeaways
Two of these words describe a whole group of machines, and three name a specific mechanism or product line. The table sorts them out.
| Term | What it means | Mechanism | StairMaster examples at PGE |
|---|---|---|---|
| Stair climber | The everyday umbrella term for any machine that simulates climbing stairs | Either a revolving staircase or stepping pedals | 4G, 8Gx, 10G and the 8 Series FreeClimber |
| StepMill | A stair climber with a motorised revolving staircase of real steps | Revolving staircase | 4G StepMill, 8Gx, 10G |
| Gauntlet | The name for StairMaster's current StepMill range | Revolving staircase | 4G, 8Gx, 10G |
| Stair stepper | Usually a pedal machine; sometimes used loosely for any stair machine | Usually stepping pedals | 8 Series FreeClimber |
| FreeClimber | StairMaster's stair climber with two independent stepping pedals | Independent pedals | 8 Series FreeClimber |
Core Health & Fitness, which owns StairMaster, groups the 4G StepMill and the 8FC FreeClimber under the same "Climbing" heading on its own website. That is the clearest sign that these are two mechanisms within one family, not rival categories.
Yes. Every StepMill is a stair climber; not every stair climber is a StepMill.
The word "StepMill" tells you something extra: the machine carries a revolving staircase. Steps rise up from beneath the machine and roll towards you, and you keep climbing to stay in place, much like walking up a slow escalator that is moving down.
That is why the StairMaster 4G is correctly described as both a StepMill and a stair climber. Buying one is not a choice between the two terms.
StairMaster 4G Gauntlet StepmillFrom £3,495View product →
StairMaster 8Gx Gauntlet StepmillFrom £4,995View product →
On a StepMill the staircase moves and you climb it. On the FreeClimber the pedals move and you push them down. Every practical difference follows from that.
| StepMill (StairMaster 4G, 8Gx, 10G) | FreeClimber (StairMaster 8 Series) | |
|---|---|---|
| Mechanism | Motorised revolving staircase with real steps | Two independent pedals on a four-bar linkage |
| Where you stand | On a moving step, raised above the floor | On the pedals, close to floor level |
| Do you step down? | You step up onto each new stair | Never; each pedal rises again under spring tension |
| Can each leg work at its own pace? | No, the staircase sets one rhythm for both | Yes, the pedals are mechanically independent |
| Step height | Fixed: 15cm (4G), 20cm (8Gx, 10G) | Adjustable from 2.5cm to 36cm |
| Ceiling needed | 2.44m (4G); 3.05m (8Gx, 10G) | Machine is 173cm tall; no recommended figure published |
| Power | 12V/5A supply on the 8Gx and 10G | None with the Apex LED console; 12V/5A with the touchscreen |
| Maximum user weight | 159kg (4G); 181kg (8Gx, 10G) | 159kg |
| Price at PGE | £3,495 – £8,895 | £3,766 – £9,995 |
Prices and specifications come from our live product pages, and the FreeClimber figures match Core Health & Fitness's published 8FC specification.
Gauntlet is the name for StairMaster's current StepMill range: the compact 4G, the commercial 8Gx and the flagship 10G. All three use the same revolving-staircase principle; they differ in size, step dimensions, user limit and warranty.
Our complete StairMaster buyer's guide compares the three in detail.
Broadly, yes: it is a pedal-type stair climber, which is what most people mean by a stair stepper. It is a much more capable machine than a basic stepper, though.
Many simple steppers link the two pedals, so pushing one down lifts the other. The FreeClimber's pedals are independent, each on a four-bar linkage that keeps the pedal level through its travel, so a weaker leg is never dragged into the stronger leg's rhythm. The step height also runs from a 2.5cm shuffle to a 36cm climb.
That design traces back to a 1986 patent filing by StairMaster co-founder Lanny Potts, US Patent 4,708,338, which describes each pedal "operating independently" of the other. The full story is in our 8 Series FreeClimber guide.
StairMaster FC 8 Series FreeClimber£3,766 – £9,995View product →
StairMaster 10G Gauntlet Stepmill£7,375 – £8,895View product →
Because each solves a different problem, and the company invented both. According to Smithsonian Magazine's history of StairMaster, the founders' first machine in 1983 was a revolving staircase, designed to give the effort of climbing stairs without the descent.
A pedal machine followed in the late 1980s, built around independent pedals. The staircase gives the most realistic, demanding climb; the pedals give a gentler, more adjustable one that more people can use.
That history also explains why "StairMaster" is used casually for any stair machine in a gym. The brand name stuck to both mechanisms.
A StepMill feels like real stairs. Each step is a full step-up onto a moving stair, so your glutes, quads and hamstrings work through a long range while your heart rate climbs fast. At the 8Gx's top speed of 190 steps per minute, it is one of the hardest stations on any gym floor.
The FreeClimber feels smoother and more controlled. You stay low, press each pedal down and let it rise again. With no step up and no step down, it is gentler on knees and easier to start on, yet set to a deep step it is still hard work.
Neither is simply better. Fit users chasing the toughest climb tend to prefer a StepMill; people returning from injury, older members and anyone put off by a moving staircase usually get on better with the FreeClimber.
Let the room and the user decide. This is how we match them.
| Your situation | Mechanism | StairMaster model |
|---|---|---|
| Home gym with at least 2.44m of headroom | Revolving staircase | 4G StepMill |
| Home gym with a lower ceiling | Independent pedals | 8 Series FreeClimber |
| Knee concerns, rehab or uneven leg strength | Independent pedals | 8 Series FreeClimber |
| Garage or outbuilding with no spare socket | Independent pedals (Apex LED console) | 8 Series FreeClimber |
| Membership gym floor | Revolving staircase | 8Gx |
| Athletic or tactical training under load | Revolving staircase | 10G with OverDrive |
| Mixed-ability commercial floor | Both | A Gauntlet StepMill alongside a FreeClimber |
For model-by-model advice, see our guides to the best StairMaster for a home gym and the best StairMaster for commercial gyms.
Four things, whichever mechanism you choose.
Our StairMaster ceiling height guide shows how to measure the height that counts.
For most people who will use it regularly, yes. Prieto-González and Yagin's 2024 study in Frontiers in Sports and Active Living compared seven indoor machines and recorded 13.35 kcal per minute on a stair climber at hard effort, second only to the treadmill. The paper does not say which mechanism its machine used, so treat the figure as evidence for stair climbing in general.
The NHS recommends adults do at least 150 minutes of moderate or 75 minutes of vigorous activity each week. On either mechanism, a short daily climb at a hard pace covers the vigorous option.
The international safety standard ISO 20957-8:2017 covers both mechanisms in one document, under its own heading of "steppers, stairclimbers and climbers".
Free UK delivery on every StairMaster StepMill and the FreeClimber. Orders are dispatched within 5 working days, with tracking emailed within 24 hours of dispatch, and delivered across UK mainland by our delivery partners.
You can choose courier delivery to assemble yourself, pre-assembled delivery that arrives ready to use, or full installation arranged on site. Installation is quoted separately before you order, so ask when you enquire.
Tell us your ceiling height, who will use the machine and whether there is a socket nearby, and we'll recommend a StepMill or the FreeClimber before you order. Business finance available on orders from £5,000.
See all stair climbers → Call 0333 880 3211By the room first and the mechanism second. Our StairMaster conversations start with ceiling height, floor and access, because those rule a mechanism in or out before price or console come up.
The StairMaster most recently bought through our checkout was a 4G StepMill in September 2026, ordered with pre-assembled delivery and installation: the revolving-staircase model designed for a standard-height room.
What is the difference between a StepMill and a stair climber? There isn't a difference in category: a StepMill is one kind of stair climber. "Stair climber" is the general term for machines that simulate climbing stairs, while "StepMill" means the specific design with a revolving staircase of real steps. StairMaster's StepMills are the 4G, 8Gx and 10G. The machine with a genuinely different mechanism is the FreeClimber, which uses independent pedals.
Is a StairMaster a StepMill or a stepper? StairMaster is a brand that makes both. Its Gauntlet models, the 4G, 8Gx and 10G, are StepMills with a revolving staircase. Its 8 Series FreeClimber is a pedal-type stair climber. In a gym, "the StairMaster" usually refers to whichever stair machine is on the floor.
Is the FreeClimber easier on the knees than a StepMill? Usually, yes. On the FreeClimber you never step up onto a stair or step down from one; you press independent pedals that return under spring tension, and the step can be as shallow as 2.5cm. A StepMill involves a full step-up on every stair. Anyone recovering from injury should follow advice from their physiotherapist.
Which needs less headroom, a StepMill or the FreeClimber? The FreeClimber. It stands 173cm tall and keeps you near floor level, whereas StairMaster recommends a 2.44m ceiling for the 4G StepMill and 3.05m for the 8Gx and 10G. StairMaster does not publish a ceiling figure for the FreeClimber, so send us your room height and we will confirm it.
What is a stair stepper? Most people use "stair stepper" for a machine with two pedals that you push down, rather than a revolving staircase. Some shoppers use it loosely for any stair machine. In StairMaster's range, the pedal machine is the 8 Series FreeClimber, which goes further than a basic stepper with fully independent pedals and an adjustable step height.
Do StepMills and the FreeClimber need a power socket? The 8Gx and 10G StepMills need a 12V/5A supply at the machine. The FreeClimber's Apex LED console generates its own power as you climb and needs no socket, while its Apex 16 inch HD Touch needs a 12V/5A supply. For the 4G, ask us to confirm the requirement for your chosen console.
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Pro Gym Essentials — premium home and commercial gym equipment, delivered across the UK. Specifications and prices taken from our live product pages and Core Health & Fitness's published StepMill and FreeClimber specifications, 4 October 2026.
