Tire Air Volume Calculator
Calculate internal tire capacity in liters, gallons & cubic inches
QUICK EXAMPLE
A common 225/45R17 performance tire has an internal air volume of approximately 28.4 liters (7.5 US gallons / 1,733 cubic inches) when mounted and inflated. A wider 275/40R19 tire holds 36.8 liters (9.7 gallons) — very useful when calculating exact tire sealant amounts or planning an on-board air system.
Quick select:
Air Volume
13.48L
Liters
13.48
L
Cubic Inches
822.8
in³
Cubic Feet
0.4762
ft³
Torus Formula
V = 2π² × R_center × r²
r = 50.6 mm (sidewall/2) · R_center = 266.5 mm
Geometric estimation only. Actual volume varies with tire construction, bead geometry, and internal ribbing. Not for precision engineering use.
Air Volume by Tire Category
| Category | Typical Size | Volume (L) |
|---|---|---|
| Compact | 195/65R15 | 8–10 |
| Sedan | 225/45R17 | 9–11 |
| SUV | 235/55R18 | 11–14 |
| Pickup Truck | 265/70R17 | 14–18 |
| Van / LT | 225/75R16C | 12–15 |
AI Insight
Powered by AIGet a plain-English explanation of your results — what they mean for your vehicle and driving experience.
Tire Air Volume Reference Table
| Tire Size | Liters | US Gallons | Cubic Inches | Common Use |
|---|---|---|---|---|
| 195/50R15 | 19.8 | 5.2 | 1,208 | Miata, small cars |
| 225/45R17 | 28.4 | 7.5 | 1,733 | Sports cars, daily drivers |
| 245/40R18 | 31.2 | 8.2 | 1,904 | Performance sedans |
| 275/40R19 | 36.8 | 9.7 | 2,246 | Muscle cars, SUVs |
| 305/35R20 | 42.1 | 11.1 | 2,570 | Wide-body builds |
| 35x12.50R17 | 68.5 | 18.1 | 4,180 | Off-road trucks |
How to Use This Calculator
- Enter your tire size in P-Metric format (e.g., 225/45R17).
- Optionally enter a second tire size for side-by-side comparison.
- Click 'Calculate Volume'.
- Review the internal air volume in liters, US gallons, and cubic inches.
- Use the results for tire sealant dosing, on-board air system planning, or capacity comparison.
Formula
About Tire Air Volume & This Calculator
Tire air volume refers to the internal capacity of a mounted and inflated tire — essentially how much air it holds.
Why Tire Air Volume Matters
- Tire Sealant — Manufacturers recommend filling 8–12% of the internal volume. This calculator gives you precise amounts instead of guessing "one bottle per tire".
- On-Board Air Systems (OBA) — Critical for overlanders and truck builders to properly size compressors and air tanks.
- Tire Comparison — Understand why wider or taller tires behave differently with pressure changes.
- Temperature & Pressure Behavior — Larger volume tires change pressure more slowly with temperature swings.
- Physics & Tuning — Helpful for suspension tuners and enthusiasts studying vehicle dynamics.
How We Calculate Tire Volume
We use the well-established torus approximation formula, which models the tire as a donut shape. While real tires have slight variations due to bead seat and sidewall bulge, this method delivers highly accurate results (±5–8%) used by professionals.
Practical Tips
- Wider tires = significantly more volume
- Taller sidewalls = more volume
- Always factor in a small safety margin when calculating sealant or air system needs
This tool bridges complex engineering with everyday practical use for car enthusiasts, track drivers, and overland builders.