Gravel bike tire pressure calculator
Gravel pressure is a trade-off between speed on smooth sections and grip and comfort on rough ones. A 75 kg rider on 40 mm tubeless tyres on mixed gravel typically runs about 41 psi front and 45 psi rear. Enter your weight, tyre width and the gravel you ride for front and rear pressures.
Use the measured width on your rim if you know it; wide rims make tyres measure wider.
Advanced
Enter a value between 15 and 220 psi.
Starting range: front 40 to 42 psi, rear 44 to 46 psi. Adjust 2 to 3 psi at a time.
Base pressure by tyre width at 80 kg total weight, scaled with weight, adjusted for surface, setup and weather. Front about 5 % lower and rear about 5 % higher than the base.
How gravel tyre pressure is calculated
Gravel is the hardest discipline to set pressure for, because one ride can mix tarmac, hardpack, loose stones and rutted tracks. Too hard and the bike skips on rough sections. Too soft and it feels vague on tarmac, and the rim can hit stones. This calculator is one of the free LeCoach cycling calculators, set up for gravel tyres from 35 to 50 mm.
It uses a base pressure for each width at a total system weight of 80 kg, on hardpack, tubeless and dry. A 40 mm tyre starts at 43 psi and a 45 mm tyre at 35 psi. The base scales in a straight line with your weight, then drops for rougher gravel:
- Hardpack or mostly tarmac: no change
- Mixed gravel: 6 % lower
- Rough or chunky gravel: 12 % lower
The front then goes 5 % below and the rear 5 % above the base.
Gravel tyre pressure by rider weight and width
Mixed gravel, tubeless, dry, 10 kg bike. Each cell shows front / rear in psi, with bar in brackets.
| Rider | 38 mm | 40 mm | 45 mm | 50 mm |
|---|---|---|---|---|
| 60 kg | 37 / 41 (2.6 / 2.8) | 34 / 37 (2.3 / 2.6) | 27 / 30 (1.9 / 2.1) | 23 / 25 (1.6 / 1.7) |
| 70 kg | 42 / 46 (2.9 / 3.2) | 38 / 42 (2.6 / 2.9) | 31 / 35 (2.1 / 2.4) | 26 / 29 (1.8 / 2.0) |
| 80 kg | 47 / 52 (3.2 / 3.6) | 43 / 48 (3.0 / 3.3) | 35 / 39 (2.4 / 2.7) | 29 / 32 (2.0 / 2.2) |
| 90 kg | 52 / 58 (3.6 / 4.0) | 48 / 53 (3.3 / 3.7) | 39 / 43 (2.7 / 3.0) | 32 / 36 (2.2 / 2.5) |
Width matters a lot here. Going from 40 to 45 mm drops pressure by about 7 to 10 psi for the same rider, and 50 mm tyres let a 90 kg rider run less than a 70 kg rider on 40 mm.
Choosing the right surface setting
The surface setting is where most riders get gravel pressure wrong. For a 75 kg rider and 10 kg bike, front / rear in psi (bar):
| Surface | 40 mm tyres | 45 mm tyres |
|---|---|---|
| Hardpack or mostly tarmac | 43 / 48 (3.0 / 3.3) | 35 / 39 (2.4 / 2.7) |
| Mixed gravel | 41 / 45 (2.8 / 3.1) | 33 / 37 (2.3 / 2.6) |
| Rough or chunky gravel | 38 / 42 (2.6 / 2.9) | 31 / 34 (2.1 / 2.3) |
On a mixed-surface ride, set pressure for the roughest long section, not the smoothest. A few kilometres of tarmac slightly soft cost you little; hours of rough gravel too hard cost grip, comfort and energy. Mostly tarmac with short gravel sectors: hardpack. Mostly gravel with the odd road link: mixed. Loose, rocky or rutted: rough.
Want this worked out for you every day? LeCoach builds your training around your own numbers.
Try LeCoach for freeWhy not go as low as possible?
This calculator is deliberately a little firmer than the lowest modern recommendations, because the downsides of going too low arrive suddenly:
- Rim strikes. A sharp stone can push the tyre into the rim, which can dent a rim or cut the tyre.
- Burping. In a hard corner a soft tyre can roll on the rim and let air escape past the bead.
- Vague and slow. The tyre squirms in corners, and on smooth sections a tyre that flexes too much wastes energy.
The calculator will not go below 22 psi on a gravel tyre. A 60 kg rider with a 10 kg bike on 50 mm tyres on rough gravel already sits at 22 / 23 psi (1.5 / 1.6 bar), right on that floor. If you need softer than that, your terrain probably calls for a mountain bike and the mountain bike tire pressure calculator.
Tubes, tubeless and wet gravel
- Tubeless is the default, and on gravel it matters most: no tube to pinch on sharp stones, and sealant plugs small cuts. Stan's NoTubes says its sealant performs for about 2 to 7 months, less in dry climates, so check it before a big event.
- Inner tubes add 6 %. On 40 mm tyres on mixed gravel, the example rider goes to 43 / 48 psi (3.0 / 3.3 bar).
- Wet or muddy gravel takes off 5 %: 39 / 43 psi (2.7 / 3.0 bar) on 40 mm tyres.
Common gravel mistakes
- Leaving out the luggage. Frame bag, bottles and spares all belong in the bike weight.
- Road habits. A gravel tyre at road-like pressure skips over loose stones and loses grip.
- Matching front and rear. Off-road, the front needs grip for steering and braking; the rear needs support.
- Ignoring the measured width. On wide rims gravel tyres often measure wider than the label.
- Forgetting the sealant. Dried-out sealant means no puncture protection.
When to change your gravel pressure
- After rain: switch on "Wet conditions".
- New or worn tyres: re-enter the width; see when to replace bike tires.
Before an event, run through the race day checklist and plan your carbs and fluids with the race nutrition calculator. The bike tire pressure calculator covers all bikes. And ask LeCoach how to pace and fuel your next gravel event: it answers from your own rides, not a generic chart.
Sources
- Berto F. Tire drop pressure chart. Bicycle Quarterly. https://www.renehersecycles.com/wp-content/uploads/2015/03/BQTireDrop.pdf
- road.cc. How to choose your tyre pressure. https://road.cc/content/feature/how-choose-your-tyre-pressure-180830
- Stan's NoTubes. Sealant service life guidance.
Frequently asked questions
What psi should gravel tyres be?
For a 75 kg rider with a 10 kg bike on 40 mm tubeless tyres on mixed gravel, start at about 41 psi front and 45 psi rear (2.8 and 3.1 bar). Hardpack calls for a few psi more, rough gravel a few less, and wider tyres lower still.
What pressure for 40 mm vs 45 mm gravel tyres?
A 45 mm tyre runs about 7 to 10 psi lower than a 40 mm tyre for the same rider. With a 75 kg rider and a 10 kg bike on mixed gravel, that is 41 / 45 psi on 40 mm against 33 / 37 psi on 45 mm.
How low can you run gravel tyre pressure?
This calculator does not go below 22 psi on a gravel tyre, and for most riders the right number is well above that. Very low pressures risk rim strikes, burping and vague handling. If your weight and terrain push you to the floor, a wider tyre is the safer way to get more comfort.
What gravel tyre pressure for a race with tarmac sections?
Set pressure for the longest rough sections, not the tarmac. A tyre a few psi too soft on tarmac costs you little; one that is too hard on rough gravel costs grip and comfort for hours. If the route is mostly tarmac with short gravel sectors, choose the hardpack setting instead.
Do I need tubeless tyres for gravel?
You do not need them, but they help. Without a tube, there is nothing for sharp stones to pinch against the rim, and sealant closes small cuts. With inner tubes the calculator adds 6 % to reduce pinch flats, so you lose some comfort and grip on rough sections.
Why does my gravel tyre burp air?
Burping happens when a soft tyre rolls sideways in a hard corner or landing and the bead briefly lifts from the rim, letting air and sealant escape. Pressure that is too low is the most common cause. Add 2 to 3 psi and check that the tyre is seated well on the rim.
Ready for your next gravel event?
Long gravel days need endurance. LeCoach builds it week by week, with every workout written for you.
Try LeCoach for freeIn this topic
Related calculators
Front and rear tyre pressure for road, gravel and MTB from your weight, tyre width and surface.
Open calculator →Road tyre pressure for 23 to 35 mm tyres, tubeless or tubes, with the hookless 72.5 psi limit built in.
Open calculator →MTB tyre pressure for 2.2 to 2.6 inch tyres by trail type, casing and inserts.
Open calculator →