This tyre pressure calculator gives a fast assessment of front and rear pressures for bicycles, motorcycles, scooters and e-scooters. The tool uses factory recommendations or model guidelines, applies a simple temperature correction and highlights status with color zones and clear labels. Use the result as a practical guide, not a substitute for factory instructions or professional gauges.
🚲 Results are indicative. For precise setup use a calibrated gauge and follow tyre and vehicle manufacturer guidance.
Table of Contents
Input data
- Category — choose bicycle, motorcycle, scooter, e-scooter or e-bike.
- Model or subtype — selects recommended pressure for tyre width and diameter or manufacturer data.
- Units — bar or psi. Values convert automatically when units change.
- Recommended pressure front / rear — prefilled from model or entered manually.
- Measured pressure front / rear — user reading from a gauge.
- Tire temperature — used for a simple linear correction because pressure rises with temperature.
What the calculator provides
- Temperature adjusted pressure using a small linear correction.
- Difference between measured and recommended pressure and a status label OK, Overinflated, Underinflated or Severely off.
- Animated dial visuals with color bands for normal, warning and danger.
- Summary table and option to export a snapshot of results.
- Notes on when to retest and practical tips for measurement consistency.
Formulas
Use SI or imperial units. For a simple temperature correction in bar:
\[
P_{\text{corr}} = P_{\text{meas}} + k \cdot (T – 20)
\]
where \(P_{\text{meas}}\) is measured pressure in bar, \(T\) is tyre temperature in degrees Celsius, and \(k \approx 0.001\) bar per degree Celsius.
If you work in psi use this approximate factor:
\[
P_{\text{corr,psi}} = P_{\text{meas,psi}} + 0.0145 \cdot (T – 20)
\]
Difference and normalized deviation:
\[
\Delta P = P_{\text{corr}} – P_{\text{rec}}
\]
\[
\delta = \frac{\Delta P}{P_{\text{rec}}}
\]
Status criteria
- If \(|\delta| \le 0.06\), status is OK.
- If \(0.06 < \delta \le 0.15\), status is Overinflated.
- If \(-0.20 \le \delta < -0.06\), status is Underinflated.
- Otherwise status is Severely overinflated or Severely underinflated.
Worked examples — numbers changed
Road bike 23c — example in psi
Recommendation: front 102 psi, rear 109 psi. Measured: front 99 psi, rear 104 psi, tyre temperature 72 °F which is about 22 °C.
- Temperature correction in psi: \(P_{\text{corr}} = 99 + 0.0145\cdot(22-20) \approx 99.03\) psi so display 99.0 psi.
- \(\Delta P_{\text{front}} = 99.03 – 102 = -2.97\) psi, relative \(\delta \approx -0.029\) so status is OK.
- Rear corrected 104.03 psi, \(\Delta = -5.0\) psi, \(\delta \approx -0.046\) still OK.
Xiaomi M365 e-scooter — example in psi
Recommendation: 36 psi front and rear. Measured 29 psi, tyre temperature 86 °F which is about 30 °C.
- Correction: \(P_{\text{corr}} = 29 + 0.0145\cdot(30-20) \approx 29.145\) psi.
- \(\Delta P = 29.145 – 36 = -6.855\) psi, normalized \(\delta \approx -0.190\) so status is Underinflated and near the severe threshold.
Reference tables — typical values in psi
Road tyres
| Tyre | Front psi | Rear psi | Note |
|---|---|---|---|
| Light road 23c | 95–105 | 102–112 | Narrow tyres need high pressure |
| Standard 25c | 88–98 | 95–105 | Common compromise for mixed use |
| Endurance 28c | 82–92 | 88–98 | Comfort oriented |
Gravel and mixed
| Tyre | Front psi | Rear psi | Note |
|---|---|---|---|
| Gravel 35 mm | 55–65 | 60–70 | Lower for traction on loose surfaces |
| Gravel 40 mm | 48–58 | 52–62 | Tubeless allows lower pressure |
MTB and plus
| Tyre | Front psi | Rear psi | Note |
|---|---|---|---|
| Trail 29 2.3″ | 26–30 | 28–32 | Adjust for terrain |
| Enduro 2.5″ | 22–26 | 24–28 | Lower for grip off-road |
Urban e-bikes and cargo
| Model | Front psi | Rear psi | Note |
|---|---|---|---|
| Urban e-bike | 52–58 | 58–68 | Higher rear pressure for load |
| Cargo bike | 45–55 | 65–85 | Heavy payload needs higher rear pressure |
Practical recommendations and testing tips
- Always check pressure cold before a ride. Measure at the same valve and use the same gauge to avoid bias.
- Calibrate or compare your gauge against a trusted reference periodically.
- Small portable pumps can overshoot the top of the scale. Use a digital gauge for final tuning.
- For long rides start slightly lower and recheck after the first few miles. Temperature rise increases pressure and changes feel.
- Tubeless tyres allow safer pressure reduction, but monitor for burping or rim contact at low values.
- Excessive overinflation reduces contact patch and grip. Too low pressure increases rolling resistance and risk of pinch flats.
- For electric transport track pressure and energy use. Underinflation increases rolling drag and reduces range.
- Perform small A/B tests: change pressure by a small step, ride a representative route and compare ride quality, handling and wear.
This tyre pressure guide helps set safe and efficient pressures fast. Use conservative values for wet or loaded conditions and confirm with a precise gauge for critical tasks.
Recommended reading
- “Tire and Vehicle Dynamics” by Hans B. Pacejka
- “Fundamentals of Vehicle Dynamics” by Thomas D. Gillespie
- “Bicycling Science” by David Gordon Wilson
David Parry — Senior Engineering Analyst
Specializing in electronics and physics-based simulations with 20+ years of engineering experience. David ensures the mathematical and physical accuracy of the tools at ProCalcLab.
