Chest Press vs Bench Press: Which Builds a Better Chest?

For building your chest, the machine chest press and the barbell bench press are about equally good, and the research backs that up. Pick the chest press machine if you're a beginner, you train alone, or you want to push sets right to failure without a bar over your throat. Pick the bench press if you want a strength number that means something outside your own gym, or you plan to compete in powerlifting, because the barbell bench is a skill and you only get good at it by doing it.

Most people with access to both should use both. Which one goes first in your session depends on what you're chasing, and the sections below set out how to decide.

Chest press vs bench press at a glance

	Machine chest press	Barbell bench press
Position	Seated upright, back against a pad	Lying on a flat bench under a racked bar
Path of the weight	Fixed by the machine	Free; you steer a shallow curve from chest to lockout
Main muscles	Pecs, front delts, triceps	Pecs, front delts, triceps
Stabiliser demand	Low; the machine does the balancing	Higher; shoulders, upper back and grip keep the bar steady
Learning curve	Minutes: set the seat, pick a weight, push	Weeks to months to groove setup, bar path and leg drive
Failing a rep alone	Safe; the handles return to the stack	Risky without a spotter or safety bars
Chest muscle growth	Similar to the bench in trials	Similar to the machine in trials
Strength carryover	Mostly to that machine	Mostly to the barbell bench, the lift people compare and compete in
Comparing numbers	Meaningless between machines	Standardised: a 20kg bar plus plates weighs the same anywhere
Home setup	A multi gym with a press arm	A bench, a barbell, plates and a rack with safeties

How the two lifts differ

On a chest press machine you sit with your back on a pad and push two handles forwards along a track the manufacturer chose. Resistance comes from a pin-loaded weight stack or from plates hung on lever arms. You can't drift off line and the weight can't land on you, so the only job left is pushing.

The bench press has you lying under a bar with nothing guiding it. You have to unrack it, lower it to your lower chest, then press it up and slightly back towards your face while your shoulder blades stay pinned to the bench. That extra control is why the bench takes far longer to learn, and it's also why a 100kg bench earns more respect than 100kg on a stack.

There's a middle option. A Smith machine bench press keeps the lying position and the real bar but runs it on rails, which removes most of the balancing and gives you hooks to catch a failed rep.

Muscles worked: what the EMG studies found

Both lifts are driven by the pectoralis major, with the front delts and triceps helping. The question people actually ask is whether the machine works the chest less. On the evidence we could find, it doesn't.

A 2023 study had 20 physically active adults do 8 reps at 60% of their max on the flat bench press and on the seated chest press with different grips. Front delt activity didn't differ between any of them. The upper (clavicular) part of the pec was actually a little more active on the neutral grip chest press than on a wide grip bench, at roughly 30% versus 25% of a maximal contraction, and the authors concluded that all the exercises and grips produced similar muscle activity (Muyor and colleagues, Journal of Human Kinetics).

A second study muddies the upper chest finding. Ten competitive bodybuilders pressed 80% of their max on flat, incline and decline benches and on a chest press machine. The mid and lower (sternocostal) pec worked equally hard on the flat bench and the machine, but the upper pec was less active on the machine, and the triceps and side delts worked harder on the free weight presses, which the researchers put down to the bar's instability (Coratella and colleagues, European Journal of Sport Science).

So two small studies agree on the mid chest and disagree on the upper chest, most likely because they used different machines, grips, loads and lifters. Our reading: either lift trains the bulk of your chest hard, the barbell gives your triceps and the muscles around your shoulders more to do, and neither is a reliable upper chest builder on its own. An incline press does that job better.

Smith machine research points the same way. Twelve trained men showed no difference in pec or front delt activity between a Smith machine press and a barbell press, even though the barbell is the less stable of the two (Saeterbakken and colleagues, Journal of Sports Sciences).

Muscle growth and strength: what the training studies found

The most relevant trial for this comparison ran at the University of Murcia. Thirty-eight trained men followed the same 8 week programme, with half using barbells and half using machines for the squat, bench press, row and shoulder press. Ultrasound showed the pectoralis major grew in both groups with no significant difference between them, and each group gained strength on both kinds of equipment but gained most on the kind it had trained with (Hernández-Belmonte and colleagues, Medicine and Science in Sports and Exercise).

A meta-analysis from the same year pooled 13 studies and 1,016 people. It found no difference in muscle growth between free weight and machine training. Free weight strength improved more with free weight training; machine strength tended to improve more with machine training, though that second result fell just short of statistical significance (Haugen and colleagues, BMC Sports Science, Medicine and Rehabilitation).

One Canadian study adds a wrinkle. Forty-six men and women trained for 8 weeks on free weights or machines. Machine bench press strength rose 13.9% in the machine group against 8.6% in the free weight group, yet free weight bench strength went up by a similar amount in both (Schwanbeck and colleagues, Journal of Strength and Conditioning Research). That study measured muscle thickness in the biceps and quads, not the chest, so it tells us about strength more than pec size.

Put together, the pattern is consistent. Your chest grows about the same on either, and you get strongest at whichever press you practise. These trials lasted around 8 weeks, mind, and nobody has run a multi-year version.

Why your numbers don't match, and why there's no conversion

Search for a chest press to bench press conversion and you'll find confident percentages. Ignore them. No fixed ratio exists, for reasons that come down to how machines are built.

• The stack label isn't the force at the handles. Cables, pulleys, cams and lever arms sit between the plates and your hands, and each design changes how heavy a given pin setting feels. Two machines in the same gym can differ noticeably at "50kg".
• Plate-loaded arms have their own weight. The empty lever arms on a plate-loaded press weigh something before you add a plate, and manufacturers don't always publish the figure.
• The strength curve differs. Some machines are hardest at the start of the push and easier near lockout, others the reverse. A barbell weighs the same throughout, and the sticking point sits a few centimetres off the chest.
• The bench uses more of you. Leg drive, an arched upper back and a practised bar path all add kilos to a barbell bench. None of them help much in a seat.
• Stability costs force. Steadying a free bar takes effort the machine spares you. In the Saeterbakken study, the same lifters pressed 17% less with dumbbells than with a barbell purely because dumbbells are harder to control.

Most gym-goers move more on the machine than on the bar. Some find the opposite, usually because their machine starts them in a deep, stretched position. Both are normal.

If you're moving from the machine to the barbell, treat it as a new lift. Start with the empty 20kg bar for a few sets of 8, add 5kg or 10kg at a time while the reps stay smooth, and stop at a weight you could press for about two more reps. That's your starting point, and it takes one session to find. Track each lift against its own history from then on.

Which should you pick?

Beginners. Start on the machine if you train alone or feel nervous under a bar. You'll learn to keep your shoulder blades back and your elbows below shoulder height with no risk of getting stuck, and those habits transfer. If someone can teach you the bench properly, there's no reason to wait; run both from week one.

Muscle growth. Use whichever lets you train hardest with the least fuss. The machine has a practical edge here: you can take every set to within a rep of failure, change the weight in seconds for drop sets, and still feel your chest working when your shoulders and grip are tired. That makes it a good second press after a heavier barbell or dumbbell lift.

Strength and powerlifting. Bench press, no debate. Strength is specific to the movement, the competition lift is the barbell bench with a pause on the chest, and a machine can't teach you the setup. Use the chest press afterwards for extra chest volume if you want it.

Sore shoulders. We can't diagnose a shoulder from here, and persistent pain needs a physio. What we can say is that the fixed straight bar locks your hands into one position, while many machines offer neutral (palms facing) handles and an adjustable seat so you can find a pain-free line. In the Murcia trial, upper limb discomfort scores improved in both the barbell and machine groups with no difference between them, so neither is inherently hard on healthy joints. A dumbbell bench press or a cable chest press gives you the same freedom to rotate your hands.

Training alone at home. Never bench heavy alone without safety bars. A barbell bench at home needs a power cage or a rack with safeties set just below chest height, plus a solid weight bench. If that's more steel than your spare room allows, a multi gym with a press arm or a Smith machine gives you a press you can fail on safely. Dumbbells are the cheapest safe route of all, and our barbell vs dumbbell guide covers that choice.

How to programme both

Two chest sessions a week suits most people, with somewhere between 8 and 14 hard pressing and fly sets across the week. Take most sets to within one or two reps of failure.

Strength first (you want a bigger bench):

• Bench press: 4 sets of 4 to 6 reps, 3 minutes rest.
• Machine chest press: 2 to 3 sets of 8 to 12, 90 seconds rest, last set to failure.
• Add an incline dumbbell press on your second day.

Size first (you want a bigger chest):

• Machine chest press: 3 to 4 sets of 8 to 12, the last one to failure.
• Incline press (dumbbell or Smith): 3 sets of 8 to 12.
• Bench press on the second day for 3 sets of 6 to 10, so you keep the skill.

Machine only (multi gym at home):

• Chest press: 4 sets of 8 to 12.
• Pec fly on the same station: 2 to 3 sets of 12 to 15.
• When you can hit 12 reps on every set, move the pin down one plate.

On the barbell, add 2.5kg once you reach the top of your rep range on all sets. Weight stacks often jump in bigger steps than that, so expect to add reps for a few weeks before the next plate feels manageable.

Getting a chest press at home

Standalone chest press machines are mostly commercial kit, big and heavy. At home, the chest press almost always comes as the press arm on a multi gym. Stack size is the spec to check, because a 45kg stack that suits a beginner won't challenge someone who already benches their bodyweight.

The BodyMax MG5 is the premium pick in our best multi gym guide. Its listing gives a 102kg weight stack, a chest press station and a 177 x 122 x 205cm footprint. It was £849 and in stock at the time of writing; we haven't tested it ourselves.

Check the BodyMax MG5 multi gym price on Amazon£849.00

For a full routine on that kind of machine, see our multi gym workout.

Recommended reads

• Chest press machine: setup, muscles worked and benefits
• Bench press: technique, muscles worked and how to progress
• Smith machine bench press: setup, cues and how it compares
• Best multi gyms in the UK
• Best power cages in the UK