Tongue Weight Calculator

How This Tongue Weight Calculator Works

Tongue weight is the quiet number that decides whether your trailer tows straight or fishtails down the highway. It's the downward force the trailer puts on your hitch, and getting it right is one of the most important safety steps in towing. This tongue weight calculator takes your loaded trailer weight and gives you the target tongue weight plus the acceptable range, so you can load with confidence instead of guessing and hoping it tows well.

How to Use This Calculator

One input, one clear target.

1. Enter your trailer weight. Put in your GVWR or, better, your actual fully loaded weight. The default is 3,500 lbs, and you can edit it to match your trailer.
2. Read your target tongue weight. The tool applies the 13% rule to give you the ideal tongue weight for that load.
3. Check the acceptable range. It also shows the 10% to 15% window, since anywhere in that band is considered safe.
4. Load to hit the target. Use the number to position your cargo, then confirm your tow vehicle can handle that tongue weight before you head out.

How It's Calculated

The math is simple, and it's built on a well-established towing rule. Your ideal tongue weight is 13% of the loaded trailer weight, sitting in the middle of the accepted 10% to 15% range.

Target tongue weight = loaded trailer weight x 0.13

Acceptable range = loaded weight x 0.10 to loaded weight x 0.15

Why a range instead of a single magic number? Because trailers and loads differ, and anywhere from 10% to 15% keeps the trailer tracking straight. Below 10%, the back of the trailer gets too heavy and can start to sway; above 15%, too much weight rides on the hitch and squats the back of your tow vehicle. The 13% target keeps you comfortably in the safe middle.

It helps to picture what tongue weight actually is: with the trailer level and hitched, it's the share of the total load pressing straight down on the coupler. That force is what plants the connection and stops the trailer from wagging the tow vehicle. Too little of it and the trailer floats and sways; too much and it acts like a lever lifting your front wheels. The percentage is just an easy way to scale that force to any size trailer. Here's what the target looks like across a few loaded weights:

Worked Example: A 10,000 lb Fully Loaded Trailer

Say your trailer weighs 10,000 lbs fully loaded and ready to tow.

Find the target. 10,000 x 0.13 = 1,300 lbs. That's your ideal tongue weight.

Check the range. The acceptable window is 10% to 15%, which is 1,000 lbs on the low end and 1,500 lbs on the high end. So anywhere from 1,000 to 1,500 lbs is safe, with 1,300 lbs being the sweet spot.

Load to match. If you measured your tongue weight at, say, 800 lbs, that's only 8%, too light, and the trailer would be prone to sway. You'd shift some cargo forward, ahead of the axles, to bring the tongue up into range. If it came in at 1,700 lbs (17%), you'd move cargo back to take load off the hitch. That 1,300 lb figure also matters for the rest of your setup: it counts against your tow vehicle's payload, so check the Payload Calculator and the Towing Capacity Calculator, and a tongue weight this high is where a Weight Distribution Hitch Calculator becomes worth a look.

Tips and What to Watch

Measure your actual loaded weight, don't guess. The calculation is only as good as the weight you feed it. A trailer's real loaded weight is often well above its empty weight, so use the fully loaded number for an honest target.

Too light is as dangerous as too heavy. A tongue that's too light lets the trailer sway, which can get out of control fast. A tongue that's too heavy squats your tow vehicle and lightens the steering. Aim for the 10% to 15% band, not the extremes.

Adjust with cargo position, not just cargo amount. Where you place heavy items changes tongue weight a lot. Moving weight ahead of the axles raises tongue weight; moving it behind lowers it. Small shifts can bring you into range.

Recheck whenever the load changes. A trailer you loaded perfectly last month can be out of range with a different load. Reweigh or recalculate any time the cargo changes meaningfully.

Secure the load so the balance holds. A perfect tongue weight at the driveway means nothing if cargo slides rearward at the first hard stop. Strap and block heavy items so they stay put, because a load that shifts on the road changes your tongue weight and can trigger sway mid-trip.

Frequently Asked Questions

Why 13%?

It sits right in the middle of the accepted 10% to 15% tongue weight range, which decades of towing experience have shown keeps a trailer stable. Aiming for 13% gives you a target with a safety cushion on both sides, so small loading variations still leave you in the safe window.

What if my tongue weight is outside the 10-15% range?

If it's below 10%, the trailer is too rear-heavy and can sway, so shift cargo forward. If it's above 15%, too much weight is on the hitch, so move cargo back. Adjust the load until you're back inside the range before towing.

Does tongue weight count toward my GVWR?

Everything you load counts toward the trailer's GVWR, and the tongue weight portion also transfers to your tow vehicle and counts against its payload. So it's a limit on both ends, which is why it's worth checking your tow vehicle's payload too.

How do I measure my actual tongue weight?

You can use a dedicated tongue weight scale, drive the tongue jack onto a bathroom scale for lighter trailers, or take the loaded trailer to a public scale and weigh with the tongue on and off the platform. Measuring beats estimating, especially when you're near your tow vehicle's limits.