Winch Size Calculator
Enter the loaded weight of your vehicle, the surface and the slope you may need to pull up. The calculator works out the pull needed, adds a safety margin and picks the nearest standard winch rating.
- Winch rating
- Pull needed
- Snatch block
Use the loaded weight with passengers, fuel and gear, not the empty weight.
The usual rule is a winch rated for 1.5 times the vehicle weight. Mud, sand and slopes can need far more. A 2,500 kg 4×4 in deep mud on a 20° slope needs nearly 2,400 kgf to move, so a 9,500 lb winch is the smallest that fits. A snatch block halves the pull on the winch.
Winch rating chart
1.5 × vehicle weight, minimum. Search for a weight.
| Vehicle (kg) | Vehicle (lb) | Minimum (lb) | Common rating |
|---|---|---|---|
| 400 | 882 | 1323 | 2500 |
| 800 | 1764 | 2646 | 3000 |
| 1500 | 3307 | 4960 | 5000 |
| 2000 | 4409 | 6614 | 8000 |
| 2500 | 5512 | 8267 | 9500 |
| 3000 | 6614 | 9921 | 10000 |
| 3500 | 7716 | 11574 | 12000 |
| 4500 | 9921 | 14881 | 15000 |
Rounded up to a common rating.
Slope and pull
2,500 kg vehicle in deep mud. Slide the slope.
The drawing shows the vehicle on the slope with the winch line to an anchor.
How to size a winch
Weight to rating. Step through it.
Weigh it
Loaded.
Spool the rope out to the last layer or two for the full rated pull.
Steel rope, synthetic rope or snatch block
Winch kit. Compare them.
Tough.
Light.
Pulley.
Never stand near a loaded line. Use a line damper over steel rope.
Before fitting
Winch checks. Tick each item.
Tick each item as you go.
Check the mounting plate or bumper is rated for the winch's full pull.
What you get
Winch sizing. Each tile explains one result.
Pounds.
Needed.
Included.
Derating.
Halves the load.
Winch pull drops about 10% with each layer of rope on the drum.
Frequently Asked Questions
No question matches that search.
What size winch do I need?
At least one and a half times the loaded vehicle weight, and more for mud and steep slopes.
Does a winch pull its full rating on every layer?
No. It pulls the full rating only on the first layer, and about ten per cent less for each layer after.
What does a snatch block do?
It doubles the line back, roughly halving the load on the winch at half the speed.
Is a bigger winch always better?
Not always. Bigger winches are heavier and draw more current, so match it to the vehicle.
Steel or synthetic rope?
Synthetic is lighter and safer if it breaks. Steel stands up better to rough rocks.
How much pull does mud need?
Deep mud can need half the vehicle weight or more, before any slope.
What battery does a winch need?
A healthy battery and heavy cables. Keep the engine running while winching.
Pull with margin
Choose a winch with room to spare for mud and slopes, and use a snatch block when the pull gets heavy.
More size calculators
Each one has its own calculator, worked examples and answers to common questions.