Use this RV tire pressure calculator to turn your scale weights into the load your tires carry. That load is the number you look up in your tire maker’s chart to find the right cold PSI, and it works for single tires and duals alike.
How to Use the Calculator
Weigh your RV loaded the way you travel, then enter the weight of one axle. Choose whether you weighed the whole axle or just one end, and whether each end has one tire or two. Press Calculate to see the load to look up in your chart. Our tire pressure guide shows how to get weighed and check your tires.
How RV Tire Load Is Calculated
The math is plain division. A whole-axle weight splits into two axle ends, and each end splits across the tires on it. Say your travel trailer axle weighs 5,000 lb with one tire at each end. Each end carries 2,500 lb, so each tire does too.
A motorhome with duals works the same way. A 12,000 lb rear axle puts 6,000 lb on each end, and about 3,000 lb on each of the two tires at that end. The load per tire is handy to know, but the chart in the next section reads the whole axle end.
Why You Should Weigh Each Axle End
A whole-axle weight assumes the load is split evenly, and it often is not. RV Travel notes that some RVs run closer to a 40/60 split than 50/50, so the heavier side can carry far more than the axle average suggests, and it is that side that sets your pressure.
Michelin says to weigh each axle end separately and use the heaviest end to set the cold pressure for the axle. If your scale reads 6,200 lb on one end and 5,800 lb on the other, enter 6,200 and choose One axle end.
Single or Dual Tires?
Michelin calls an axle with one tire on each end “single” and an axle with two tires on each end “dual.” Its tables show the load for one whole axle end, so you look up the weight on the end, not the weight on a single tire, even when two tires share it.
That is why duals read differently. Two tires share the end, so the Dual column lists a higher load than the Single column at the same PSI, A 6,200 lb end belongs in the Dual column as 6,200 lb, not as 3,100 lb for one tire, so read the column headings carefully.
How to Find Your PSI in the Chart
Find your tire size on the sidewall, then open the load and inflation table that matches your tire’s markings. Michelin says to match those markings and to contact a dealer if no table fits. Look down the Single or Dual column for the first load at or above your number, and read the cold PSI beside it. That PSI is your cold pressure for the axle.
Round up, never down. If your load falls between two rows, take the higher row, because it keeps you inside the tire’s capacity. Then set every tire on that axle to that pressure, even the tire on the lighter side of the axle.
What If You Can’t Get Weighed?
Your certification label, usually near the entry door, lists a cold pressure for each axle. RV Travel explains that manufacturers set it by dividing the axle’s weight rating by the number of tires on that axle. It assumes a fully loaded axle, so it cannot tell you how your own rig is loaded. Weigh your RV before a long trip.
Mistakes That Give You the Wrong PSI
Using the sidewall number. It is the tire’s maximum pressure at its maximum load, not your target. Never exceed the maximum stamped on the wheel either.
Adjusting a hot tire. A warm tire can read 10 to 15 PSI higher than its cold pressure, according to Michelin. Letting air out to reach your cold number leaves the tire underinflated once it cools, so wait for it to cool.
Using half the end load on duals. Looking up a per-tire number in the Dual column points you to a lower pressure than your load needs.
Mixing pressures on one axle. Michelin says to keep them the same across the axle, and the heavier end sets the number.
Check Your Pressure on a Schedule
Michelin recommends checking at least weekly, before a long trip, and before and after storage. It also considers a tire flat once it has run at less than 80 percent of its recommended pressure, so a tire that looks fine can already be in trouble.
Check in the morning before you drive, when the tires are cold. A tire pressure monitoring system is a useful extra, but it does not replace a gauge. Your owner’s manual and tire maker have the final say, and if your load is close to a tire’s limit, ask a tire professional.
Your Next Step
Get your RV weighed loaded for travel, enter each axle here, and write the PSI you find on a card near the driver’s seat. Not sure your load is within limits to begin with? Our payload calculator shows how much weight you can add.