How does wheel balancing work?

Wheel balancing compensates for uneven mass distribution in a tire-wheel assembly. A balancing machine spins the wheel and measures the unbalance in g·mm at each correction plane. Weights are then placed at specific locations on the rim to counteract the heavy spot, reducing vibration at speed.

What is the difference between clip-on and adhesive weights?

Clip-on weights attach to the rim flange with a metal clip and are used on steel wheels and some alloy wheels. Adhesive (stick-on) weights use a peel-and-stick backing and are placed inside the rim barrel, preferred for alloy wheels to avoid visible weights and cosmetic damage.

How much wheel unbalance is acceptable?

For passenger cars, residual unbalance below 5 g per plane is generally acceptable. Most wheel balancing machines resolve to 1–5 g. Unbalance above 10–15 g per plane usually causes noticeable steering vibration at highway speeds (80–120 km/h).

Why are two planes used for wheel balancing?

Dynamic balancing requires two correction planes (inner and outer) because unbalance can create both a static force and a couple (moment). A single plane correction only addresses static unbalance. Two-plane correction eliminates both static and dynamic unbalance for smooth operation.

What is the difference between static and dynamic balancing?

Static balancing corrects unbalance in one plane — the wheel's center of gravity is shifted back to the rotation axis. Dynamic balancing corrects in two planes (inner and outer) to eliminate both force and couple unbalance. Dynamic balancing is standard for modern vehicles as it provides complete correction.

Free Engineering Tool

Wheel Balancing Weights Calculator

Calculate the required balancing weight for vehicle wheels. Enter measured unbalance and rim diameter to find the correct clip-on or adhesive weight.

Clip-On & Adhesive 5 g Increments Inner / Outer Plane

Measured Unbalance (g·mm)

Rim Diameter (inch)

Weight Type

Correction Location

Quick presets

Results

Correction Weight Formula

The correction mass is determined from the measured unbalance and the correction radius (distance from the wheel center to the weight placement):

m_correction — required weight (grams)
U — measured unbalance (g·mm)
R — correction radius (mm)

Correction Radius from Rim Diameter

The correction radius is approximated as half the rim diameter converted to millimeters:

This assumes the weight is placed at the rim edge (flange). For adhesive weights placed further inboard, the effective radius may be smaller.

Standard Weight Increments

Wheel balancing weights come in standard 5 g increments. The calculated weight is rounded to the nearest available size:

Standard Weights (grams)
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60

Weight Types

Type	Material	Typical Use
Clip-on steel	Steel	Steel wheels, some alloy rims with flanges
Clip-on zinc	Zinc alloy	Steel/alloy wheels, lead-free alternative
Adhesive steel	Steel	Alloy wheels, hidden placement inside barrel
Adhesive zinc	Zinc alloy	Alloy wheels, lead-free, hidden placement
Lead clip-on	Lead	Legacy / classic vehicles (being phased out)

Practical Example

Example — 17″ alloy wheel

Given: Measured unbalance = 1500 g·mm, Rim diameter = 17″

R = 17 × 25.4 / 2 = 215.9 mm

m = 1500 / 215.9 = 6.95 g

Nearest standard weight: 5 g (round down) or 10 g (round up)

Best match (nearest): 5 g

⚠️ Note: Adhesive weights placed inside the rim barrel have a slightly smaller correction radius than clip-on weights at the flange. For precision, measure the actual placement radius. This calculator uses the rim edge as an approximation.