How to Squat Properly — Form, Depth and Common Mistakes
The barbell squat is the most important lower-body exercise in lifting, and the most commonly done badly. Done well, it builds the quadriceps, glutes, hamstrings and core with a weight no other exercise can match, and it is the movement that most directly transfers to everyday life — standing up from a chair is a squat. Done badly, it strains the lower back, the knees and the ego, usually because the weight was too heavy, the depth was too shallow, or the setup was rushed.
The headline answer is that a good squat starts with the bar on the upper back (not the neck), feet about shoulder-width apart with toes slightly out, and a controlled descent to at least parallel — hips below knees — with the knees tracking over the toes and the chest up. The weight should be one you can lift with that form for all sets and reps, and the depth should be consistent. Everything else — shoes, belt, stance width — is a detail that supports those fundamentals, not a replacement for them.
Use the calculator
Start with your own numbers: try our squat 1rm calculator to work out your figures before applying anything on this page. The worked examples below use round numbers so you can follow the maths; the calculators use your real weight, height, age and goal.
Related reading: How to Start Lifting Weights, Mobility Work for Lifters, How to Deadlift Properly. You can also browse the full guides section for the rest of the series.
The key points
The setup decides the rep. The bar should sit on the upper back, across the trapezius, not on the neck — the neck is not a shelf. Grip the bar just outside the shoulders, brace the core as if someone is about to poke your stomach, and unrack by straightening the legs, not by leaning forward. Take two small steps back, no more — a long walk-out wastes energy and balance. Set the feet about shoulder-width apart, toes turned out 15–30 degrees, and take a breath before each rep.
Depth matters more than weight. A squat to parallel — the crease of the hip below the top of the knee — trains the glutes and quadriceps fully and is the standard for strength and muscle. A quarter squat with a heavy weight trains the ego and the knees, not the muscles. If you cannot reach parallel, the cause is usually ankle mobility, hip mobility or a stance that does not suit your body — fix the mobility or widen the stance, rather than loading a shallow squat.
The knees should track over the toes. Knees caving inwards (valgus collapse) is the most common squat fault, and it increases knee stress and reduces force. The fix is usually to think 'knees out' — push the knees towards the little toes as you descend — and to strengthen the glutes, which control knee position. A small amount of forward knee travel is normal and safe; the knee passing the toes is not a problem, whatever old advice says.
Bracing protects the back. The lower back should stay neutral — not rounded, not excessively arched — throughout the squat, and the way to achieve that is to brace the core: take a breath into the belly, tighten the abdominals as if bracing for a punch, and hold it for the rep. A weightlifting belt helps at heavy weights, but it is not a substitute for bracing — the belt gives the core something to push against, it does not do the bracing for you.
At a glance
| Fault | What it looks like | Likely cause | Fix |
|---|---|---|---|
| Knees caving in | Knees collapse towards each other | Weak glutes, narrow stance | 'Knees out', glute work, wider stance |
| Heels lifting | Heels rise off the floor | Ankle mobility, narrow stance | Heel-raised shoes, ankle stretches |
| Chest falling | Torso leans far forward | Weak upper back, bar too high | Front squats, upper-back work |
| Shallow depth | Hips stay above knees | Mobility, too much weight | Reduce weight, mobility work |
| Rounded lower back | Back rounds at the bottom | Mobility, too much weight | Reduce depth or weight, brace harder |
The formula behind it
There is no formula for squat form, but the loading is concrete: start with a weight you can squat to parallel for 3 sets of 5 reps with good form, and add 2.5–5 kg per session until the progression slows. The depth standard is hips below knees (parallel or below), and the stance is feet about shoulder-width apart, toes out 15–30 degrees. The one-rep-max formulas (Epley, 1985; Brzycki, 1993) convert a rep-max into a 1RM estimate, which is how training percentages are set: most squat training is done at 70–85% of 1RM for sets of 5–8 reps.
Worked example — a 75 kg beginner learning to squat. Week 1: empty bar (20 kg) for 3 sets of 5, learning the setup and depth. Week 2: 30 kg. Week 3: 40 kg. Adding 5 kg per session, three sessions a week, the squat reaches 60 kg by week 5 and 80 kg by week 8 — roughly body weight, which is a solid milestone for a beginner. If depth fails at 70 kg, the weight stays at 70 kg until depth is consistent, because a shallow squat at 80 kg is worth less than a full squat at 70 kg. The progression is the programme, and form is the condition for progressing.
Your plan, step by step
- Set the bar on the upper back, grip just outside the shoulders, and brace the core before unracking.
- Take two small steps back, set the feet shoulder-width apart with toes slightly out, and take a breath.
- Descend by pushing the hips back and bending the knees together, keeping the chest up and the knees tracking over the toes.
- Reach at least parallel — hips below knees — then drive up through the whole foot, keeping the knees out.
- Film your sets from the side every few weeks and check depth, knee position and back angle against this guide.
How to use this guide
Use this guide to build a squat you can progress for years: a consistent setup, full depth, knees tracking over the toes, and a braced core. Start light, add weight slowly, and film your sets — the camera shows what the mirror hides. If a fault persists, reduce the weight and fix the fault before adding load; a squat with good form at 60 kg is worth more than a squat with bad form at 100 kg.
Common mistakes
Loading a shallow squat. A quarter squat with a heavy weight trains the ego, not the muscles. Reduce the weight until you can reach parallel on every rep, and build back up from there.
Letting the knees cave in. Knees collapsing inwards increases knee stress and reduces force. Think 'knees out', strengthen the glutes, and widen the stance if the knees still cave.
Rushing the setup. Most squat injuries happen because the setup was rushed — the bar is in the wrong place, the feet are uneven, or the core is not braced. Take the time to set up properly on every set, not just the heavy ones.
What this guide does NOT tell you
Squat guidance on this page is for healthy adults; people with knee, hip or back injuries, or other medical conditions, should discuss squatting with a clinician or physiotherapist before starting, and consider a session with a qualified trainer to check technique. Pain that is sharp, localised or worsening is not normal soreness and should be assessed. This guide is general information, not medical advice, and it does not replace individual coaching.
Frequently asked questions
How deep should I squat?
At least to parallel — the crease of the hip below the top of the knee. That depth trains the glutes and quadriceps fully and is the standard for strength and muscle. Deeper is fine if your mobility allows it, but do not sacrifice a neutral back for extra depth. If you cannot reach parallel, fix ankle or hip mobility, widen your stance, or reduce the weight — do not load a shallow squat.
Should my knees go past my toes when squatting?
Yes, a small amount of forward knee travel is normal and safe — the knee passing the toes is not a problem, whatever old advice says. What matters is that the knees track over the toes (in line with the feet) rather than caving inwards. Restricting knee travel forces the hips further back and the torso further forward, which increases lower-back stress.
Why do my knees cave in when I squat?
Usually weak glutes or a stance that is too narrow: the glutes control knee position, and when they are weak the knees collapse inwards under load. The fixes are to think 'knees out' as you descend, strengthen the glutes with hip thrusts and lunges, and widen your stance slightly. If the knees still cave at light weights, a physiotherapist can check for a structural cause.
Should I wear a weightlifting belt to squat?
A belt helps at heavy weights (above about 80% of your maximum) by giving the core something to brace against, but it is not a substitute for bracing — you still need to tighten your core. Beginners should learn to brace without a belt first, and add one only when the weights get heavy. A belt does not protect a bad squat; it supports a good one.
Is squatting bad for your knees?
No — done with good form, squatting strengthens the muscles around the knee and is associated with healthier knees, not damaged ones. The risks come from bad form (knees caving in), too much weight too soon, or an existing injury. People with knee pain should discuss squatting with a clinician or physiotherapist, and may need to adjust depth, stance or load — but the squat itself is not inherently bad for knees.
Estimates only, not medical advice. Minimum safe intakes: 1,200 kcal/day women, 1,500 kcal/day men — consult a healthcare professional before a very-low-calorie diet.