What size folding bike do I need? 16 vs 20 vs 24 inch

The short answer

Most adults should get a 20-inch folding bike. It fits most riders from about 4'8" to 6'3", rides well enough for a normal commute and still fits a car trunk or a closet. Go down to 16 inches if the bike has to fit on a crowded train. Go up to 24 inches or more if you're tall or you rarely fold it.

Folding bikes don't come in small, medium and large like regular bikes. Most use one frame, and you adjust the seatpost and stem to fit. So the real question is which wheel size suits your trip, and whether the maker's height range includes you. We haven't ridden these bikes. The numbers come from the makers' own pages, read on November 4 to 6, 2026.

Rider height, bike by bike

This is the number to check first. Makers quote a height range for each model, and it varies less than you might expect. Near the top of a range, you'll be running the seatpost close to its limit, so a bike with more room to spare will usually feel better.

• How to choose a folding bike →

16-inch: the smallest fold

Choose this if the fold matters most. Brompton's C Line folds to 23 x 22.2 x 10.6 inches, far smaller than any 20-inch bike here. FoldingBikes4U, a British retailer, rates 16-inch wheels for rides up to about 7 miles, and it says they pass on more road vibration and feel less efficient over distance.

Small doesn't mean cheap. A Brompton starts at $1,300. DAHON's K3 goes smaller still with 14-inch wheels at $699, though its stated range tops out at 6'0".

• Brompton and the other brands compared →

20-inch: the one most people should buy

It's a compromise, and a good one. You get a smoother ride than on 16-inch wheels, plenty of choice at every price and a fold that still goes in a car trunk or a closet. FoldingBikes4U says 20-inch wheels become more comfortable past about 5 miles and are the better choice from 7 to 12.

The usual folded size is about 31 x 27 x 13 inches, which is a lot bigger than a Brompton. It's manageable on a quiet train but awkward on a packed one. Amtrak allows folding bikes under 34 x 15 x 48 inches in place of a carry-on, so these fit on paper. Check your own transit system's rules too.

• The best folding bikes, most of them 20-inch →

24-inch and full size: for tall riders and longer rides

Bigger wheels ride more like a regular bike, and they suit taller riders. Tern's Node D8 has 24-inch wheels, fits riders up to 6'5" and weighs 29.3 lb. The catch is a folded size of 33.9 x 33.1 x 15.4 inches, which FoldingBikes4U says really suits people who move the bike by car.

Montague's Navigator goes further, with 700c wheels and three frame sizes: 17-inch for riders 4'8" to 5'2", 19-inch for 5'3" to 5'10" and 21-inch for 5'11" to 6'4". It's the one bike here that sizes like a regular bike, at about 29 lb and from $1,240. It folds to 36 x 28 x 12 inches, so it's fine for a trunk and no use on a rush-hour train.

How to check the fit before you buy

Start by measuring your inseam, in socks, from the floor to your crotch. Saddle height depends on it more than on your overall height, so two people of the same height can need different setups. If you're near either end of a maker's range, or you have long legs for your height, ask the maker about seatpost length.

Then look at the reach. Stem height and how far forward the handlebars sit decide how upright you'll be, and that's hard to judge from a number. Brompton's own buying guide says only a test ride can really tell you, and it's right, though it does sell bikes through dealers. If there's a shop near you with a folding bike, try one, even if it's not the model you're planning to buy. If you're buying online, check the return terms first.

• Brompton: folding bike buyer's guide →

Don't forget the weight limit

Size also means how much the bike can carry, and makers define that differently. Tern gives 231.5 lb for the rider on the Link D8 and 264.6 lb for the whole loaded bike. DAHON gives 231 lb on the K3 and the Dream D6, and ZiZZO lists a 240 lb maximum load on most of its range. So count your bag as well as yourself. The ZiZZO Forté is the one to look at if you need more, at 300 lb.

Common questions

Quick answers to what people most often ask about size.

What size folding bike do I need for my height?

If you're between about 4'8" and 6'3", a 20-inch bike should fit, but check the maker's range for that model. If you're taller, look at the Tern Node D8, which goes to 6'5", or the Montague Navigator, which goes to 6'4".

Is a 16-inch or 20-inch folding bike better?

A 20-inch bike is better for most people, because it rides more smoothly and costs less. A 16-inch bike is better if you take it on crowded trains or have very little room, since it folds much smaller.

Is a 24-inch folding bike worth it?

If you're tall, ride longer distances and mostly move the bike by car, it can be. If you need to carry it onto trains or keep it in a small space, the bigger fold will get in your way.

Can a tall person ride a folding bike?

Yes. Several makers state ranges up to about 6'3" to 6'5". Check that range, and if you can, sit on one first, because the reach can feel short even when the saddle goes high enough.

Do folding bikes come in frame sizes?

Most don't. They use one frame with an adjustable seatpost and stem. The Montague Navigator is an exception with three frames, and Brompton's 20-inch G Line also comes in sizes.

How we researched this guide

This guide is based on makers' own pages and one retailer's buying guide, not on hands-on testing. FoldingBikes4U sells folding bikes in the UK, so its distance advice comes from a seller, and its guide dates from March 2025. We earn a commission on Amazon links, and that doesn't change what we say about a bike.

• FoldingBikes4U: how to choose a folding bike →
• Tern: Link D8 →
• Tern: Node D8 →
• DAHON: K3 →
• DAHON: Dream D6 →
• ZiZZO: Campo →
• Montague: Navigator →
• Brompton: C Line →
• Brompton: which size do I need? →
• Brompton: standard seatpost →
• Brompton: extended seatpost →
• Brompton: telescopic seatpost →
• Amtrak: bikes on board →