Drag · Add · Tune · Re-balance

Where you put the load decides what your hitch holds.

Pick up any cargo box and slide it down the trailer. Tongue weight, % of GTW, and axle loads update on every pixel of motion. Keep tongue weight in the 10–15% sweet spot and you'll dodge the sway that catches new towers off guard — too far rear, the trailer fish-tails; too far forward, the hitch overloads.

Trailer Setup

Measured dry baseline

Trailer preset

Dry weight lb

Dry tongue weight lb · 11.8%

Measured baseline at the coupler with no cargo loaded.

Trailer length ft

Axle configuration

Coupler → axle ft

GVWR lb GAWR / axle lb

Find these on the trailer's VIN sticker or owner's manual.

Weight-Distributing Hitch

Trailer-side load transfer · FALR

Use weight-distributing hitch

Spring bars transfer coupler load to trailer axle

Front axle load restoration 100% FALR

Recommended bars: —

Effect summary

Trailer axle gain

+0 lb

Coupler downforce relief

−0 lb

WDH improves load distribution but does not prevent sway. Add friction sway control or use an integrated anti-sway WDH (Equal-i-zer, Reese Strait-Line, ProPride) for sway management.

Cargo Workbench

Drag any item · pick a preset

Drag any cargo · Tap to select · ←→ to nudge

Tongue Weight

—

% of GTW

—

target 10–15%

Axle Load

—

lb on trailer axle

Tongue % vs. industry target zone In safe zone

0% 10% • 15% 30%

Cargo

Drag in scene · edit here

No cargo yet — add an item or pick a preset above.

Live Calculation

Updates as you drag

Tongue weight — lb

% of GTW —target 10–15%

Trailer GVW — / — lb GVWR

Axle load — / — lb GAWR

Stability & Safety

Live coaching

—

Sway risk: low

Tongue % indicator. Green 10–15%, amber 8–10% or 15–18%, red outside that band.

Industry guideline: keep tongue weight at 10–15% of Gross Trailer Weight. Below 10% invites sway; above 15% overloads the tow vehicle's rear axle. This calculator uses the lever-arm formula T = T_dry + Σ Wᵢ · (L_axle − Lᵢ) / L_axle — measured dry tongue weight plus each cargo item's signed lever-arm contribution. WDH model transfers falr·T·OH/WB·0.6 from coupler to trailer axle (assumes OH=4.0 ft, WB=13.0 ft when truck geometry isn't known). Always verify with a real scale before towing.