| Parameter | Front axle | Rear axle |
|---|
This axle load calculator provides precise engineering estimates of how vehicle mass distributes between front and rear axles and what each wheel carries. Use the results to choose springs and dampers, check axle ratings, plan cargo placement and prevent overload.
Table of Contents
Input parameters
- Curb weight — vehicle mass without cargo and passengers in kilograms.
- Payload — passengers and cargo mass in kilograms.
- Wheelbase — distance between front and rear axle centers in meters.
- Longitudinal center of gravity position — distance from the front axle to the center of gravity in meters. Value must lie between zero and wheelbase.
- Wheels per axle — commonly two single wheels or four when dual tyres are fitted closely.
Calculated outputs
- Total vehicle mass including payload in kilograms.
- Load on front axle and rear axle in kilograms.
- Percentage load share on each axle.
- Load per wheel taking wheels per axle into account.
- Visual indicator showing center of gravity location and proportional load arrows.
Key formulas
The following relations are used to compute axle loads:
Total mass is M. Front distance is a. Rear distance is b. Wheelbase L equals a plus b.
Front axle load equals M times b divided by L.
Rear axle load equals M times a divided by L.
Per wheel load equals axle load divided by number of wheels on that axle.
Example calculation
- Curb weight 1600 kg
- Payload 420 kg
- Total mass M equals 2020 kg
- Wheelbase L equals 3.0 meters
- Center of gravity distance from front axle a equals 1.25 meters
- Then b equals L minus a which is 1.75 meters
Step by step
Front axle load equals 2020 multiplied by 1.75 divided by 3.0 equals about 1179 kilograms.
Rear axle load equals 2020 multiplied by 1.25 divided by 3.0 equals about 841 kilograms.
Front share is about 58 % and rear share about 42 %.
With two wheels per axle per wheel load is about 590 kilograms on the front and about 421 kilograms on the rear.
Reference tables
Typical axle distribution by vehicle class
| Vehicle class | Typical total mass | Front axle share | Rear axle share | Design note |
|---|---|---|---|---|
| Micro car | 700 to 950 kg | 56 to 66 % | 34 to 44 % | Strong front bias |
| Compact hatchback | 1 100 to 1 500 kg | 52 to 60 % | 40 to 48 % | Front engine layout |
| Midsize sedan | 1 450 to 1 900 kg | 50 to 58 % | 42 to 50 % | Passenger load affects front |
| SUV and wagon | 1 700 to 2 600 kg | 47 to 53 % | 47 to 53 % | Cargo location drives balance |
| Pickup with bed load | 2 200 to 3 600 kg | 30 to 45 % | 55 to 70 % | Rear load strongly increases rear axle |
| Light truck chassis | 3 000 to 7 000 kg | 40 to 60 % | 40 to 60 % | Layout dependent |
Quick conversions and checks
| Item | Value | Use |
|---|---|---|
| 1 kilogram to pounds | 2.2046 lb | Compare to imperial specs |
| 1 meter to feet | 3.2808 ft | Convert wheelbase and CG |
| Recommended safety margin | +10 percent | Apply to tyre and axle selection |
| If axle load close to rating | Redistribute cargo | Move heavy items toward center |
Practical engineering tips
- Always cross check calculated loads with manufacturer Gross Axle Weight Ratings and tyre load index values.
- Add a safety margin when choosing tyres and suspension components to allow for uneven loading and dynamic forces.
- When loading a pickup place heavy items close to the vehicle center to reduce rear axle overload.
- Include trailer tongue weight in payload calculation when towing. Tongue weight shifts CG forward and increases rear axle load of the towing vehicle.
- Use certified axle scales for final verification before registration or competition entry.
Limitations to remember
The model uses longitudinal static equilibrium only. It assumes center of gravity height has no effect on longitudinal load split. Dynamic events such as braking acceleration and cornering change axle loads. For advanced design include CG height, suspension compliance and dynamic response.
✍ Use the calculator as a reliable baseline for axle planning and safe loading. Confirm results with physical axle weighing for regulatory compliance and critical applications.
Recommended books
- Fundamentals of Vehicle Dynamics by Thomas D. Gillespie
- Vehicle Dynamics and Control by Rajesh Rajamani
- Race Car Vehicle Dynamics by Milliken and Milliken
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.
