Car Caravan Weight Calculator
Ensure safe towing, check legal limits, and calculate your 85% match ratio instantly.
Towing Match Calculator
The weight of your car with fluids and 90% fuel (often includes 75kg for driver).
Please enter a valid kerb weight.
The maximum weight your car is legally allowed to tow (check V5C/Manual).
Please enter a valid towing limit.
Max Technically Permissible Laden Mass (Fully loaded caravan weight).
Please enter a valid MTPLM.
Towing Match Ratio
87.5%
Caution (Experienced Towers)
The caravan weighs 87.5% of the car's kerb weight. This is within the legal limit but above the recommended 85% for beginners.
Legal Status (Tow Limit)
LEGAL ✓
Caravan Weight (MTPLM)
1,400 kg
Remaining Tow Capacity
600 kg
85% Guideline Weight
1,360 kg
Weight Distribution Analysis
Figure 1: Comparison of Car Kerb Weight, Towing Limit, and Caravan MTPLM relative to the 85% safety guideline.
Key Safety Thresholds
| Metric | Your Value (kg) | Safety Limit (kg) | Status |
|---|
Table 1: Detailed breakdown of your specific car and caravan weights against legal and safety limits.
Everything You Need to Know About the Car Caravan Weight Calculator
Towing a caravan requires more than just a tow bar; it requires a precise balance of weight, power, and stability. Using a car caravan weight calculator is the first and most critical step in ensuring you are legal, safe, and confident on the road. Whether you are a seasoned caravanner or a complete beginner, understanding the relationship between your car's weight and your caravan's mass is essential to avoid snaking, instability, and legal penalties.
Table of Contents
What is a Car Caravan Weight Calculator?
A car caravan weight calculator is a tool designed to determine the "Match" or "Towing Ratio" between a tow vehicle and a caravan. In the UK and Europe, this is commonly referred to as the "85% Rule". The calculator compares the caravan's Maximum Technically Permissible Laden Mass (MTPLM) against the car's Kerb Weight.
This tool is essential for:
- Beginners: Who should aim for a ratio of 85% or lower.
- Experienced Towers: Who may safely tow up to 100% of the kerb weight, provided it is within the manufacturer's towing limit.
- Legal Compliance: Ensuring the caravan does not exceed the car's maximum towing limit or Gross Train Weight (GTW).
The Car Caravan Weight Calculator Formula
The core formula used in our car caravan weight calculator is relatively simple but vital. It calculates the towing ratio as a percentage.
Towing Ratio (%) = (Caravan MTPLM ÷ Car Kerb Weight) × 100
However, a complete calculation involves checking several variables:
| Variable | Definition | Unit | Source |
|---|---|---|---|
| Kerb Weight | Mass of the car with fluids + 75kg driver | kg | V5C / Manual |
| MTPLM | Max authorized weight of the fully loaded caravan | kg | Caravan Plate |
| Towing Limit | Max weight the car is legally approved to pull | kg | VIN Plate |
| Noseweight | Vertical force on the towball | kg | Towbar Spec |
Practical Examples (Real-World Use Cases)
To better understand how the car caravan weight calculator works, let's look at two distinct scenarios.
Example 1: The Safe Match (Ideal for Beginners)
Vehicle: Ford Mondeo Estate (Kerb Weight: 1,600 kg)
Caravan: Bailey Pursuit (MTPLM: 1,300 kg)
Using the formula: (1,300 ÷ 1,600) × 100 = 81.25%
Result: This is a perfect match. The ratio is under 85%, making the outfit stable and forgiving for novice drivers. The car caravan weight calculator would display this as "Safe".
Example 2: The High Ratio (Experienced Only)
Vehicle: VW Golf Diesel (Kerb Weight: 1,350 kg)
Caravan: Swift Sprite (MTPLM: 1,300 kg)
Using the formula: (1,300 ÷ 1,350) × 100 = 96.3%
Result: While legally within the towing limit (assuming the Golf can tow 1,500kg), the ratio is 96%. This leaves little margin for error. Crosswinds or passing trucks could easily destabilize the caravan. This result would flag as "Caution" in the car caravan weight calculator.
How to Use This Car Caravan Weight Calculator
- Locate your Weights: Find your car's Kerb Weight (often mass in service) in your V5C document or owner's manual. Find the MTPLM on the data plate near the caravan door.
- Enter Data: Input these values into the "Car Kerb Weight" and "Caravan MTPLM" fields above.
- Check Limits: Input your car's "Max Towing Limit" to ensure you aren't breaking the law.
- Analyze Results: Look at the color-coded result. Green means go (under 85%), Yellow means caution (85-100%), and Red usually indicates an unsafe or illegal match (>100% or exceeding limits).
Key Factors That Affect Car Caravan Weight Results
Beyond the basic numbers provided by the car caravan weight calculator, consider these six factors:
- Actual Loading vs. MTPLM: You might not load your caravan to its maximum. However, for safety calculations, it is always best to assume the worst-case scenario (full MTPLM).
- Car Payload: Adding heavy luggage and passengers to the car increases its weight, which actually improves the towing ratio (making the car heavier relative to the caravan), but you must ensure you don't exceed the Gross Vehicle Weight (GVW).
- Noseweight: This is the downward force on the towball. Ideally, this should be 5-7% of the caravan's weight. Too light, and the caravan becomes unstable; too heavy, and the car's steering becomes light.
- Power-to-Weight Ratio: A heavy car is good for stability, but if it lacks torque (BHP/Nm), it will struggle on hills. A good match isn't just about weight; it's about performance.
- License Restrictions: In the UK, if you passed your test after Jan 1997 (and before recent changes in late 2021), there were strict limits. While rules have relaxed (B+E is now standard for many), always check your license category.
- Stabilizers: Electronic or friction stabilizers can help mitigate sway, but they cannot fix a fundamentally bad weight match identified by the car caravan weight calculator.
Frequently Asked Questions (FAQ)
1. What is the 85% rule?
The 85% rule is a guideline, not a law. It suggests that the caravan should weigh no more than 85% of the car's kerb weight to ensure the car has enough mass to control the caravan during sway or braking.
2. Is it illegal to tow at 100% ratio?
Not necessarily. As long as you do not exceed the manufacturer's specified "Max Towing Limit" and the Gross Train Weight, it is legal. However, it is not recommended for stability reasons.
3. Where can I find my car's kerb weight?
It is listed in the V5C logbook (UK) under "Mass in Service", on the VIN plate on the door pillar, or in the owner's manual.
4. Does this car caravan weight calculator account for passengers?
The standard ratio is based on Kerb Weight (empty car + fuel/driver) vs MTPLM. Passengers increase the car's weight, which mathematically improves the ratio, but you should stick to the base weights for a safety buffer.
5. Can I tow a caravan heavier than my car?
Generally, no. Even if the towing limit is high (e.g., some Land Rovers), towing a trailer heavier than the tow vehicle is dangerous at highway speeds due to the "tail wagging the dog" physics effect.
6. What happens if I exceed the towing limit?
You risk prosecution, invalidated insurance, and mechanical failure (clutch burnout, brake fade). Always use a car caravan weight calculator before purchasing a caravan.
7. Does the calculator work for twin-axle caravans?
Yes, the physics of weight ratios apply equally to single and twin-axle caravans. Twin axles are generally more stable but often heavier.
8. What is Gross Train Weight (GTW)?
GTW is the maximum allowable combined weight of the loaded car and the loaded caravan. You must never exceed this total figure.
Related Tools and Internal Resources
For more assistance with your towing setup, explore our other resources:
- Towing Capacity Checker – Look up specific vehicle limits.
- Caravan Payload Calculator – Manage your loading gear.
- Noseweight Gauge Guide – How to measure downward force.
- B+E License Guide – Understanding legal entitlements.
- Tyre Pressure Calculator for Towing – Adjusting for load.
- Fuel Cost Calculator for Towing – Estimate trip costs.