What is expected goals (xG)?

Expected goals (xG) is a metric that assigns each shot a probability of scoring between 0 and 1, based on historical data from similar shots. A shot worth 0.3 xG means an average player would score it roughly 30 percent of the time from that position and situation.

How is xG actually calculated?

Professional xG models use logistic regression or gradient boosting trained on hundreds of thousands of shots, with features like distance, angle, body part, and assist type. This calculator uses a simplified logistic model that captures the dominant effects of distance and angle.

Why does shot angle matter so much?

Angle determines how much of the goal a player can actually aim at. A shot from directly in front sees the full width of the goal, while a shot from a tight angle near the byline sees only a sliver, so even close-range chances from tight angles have low xG.

Are headers worth less xG than shots with the feet?

Generally yes. Headers are harder to direct and generate less power, so from the same location a header typically carries lower xG than a foot shot. This model applies a downward adjustment for headers to reflect that.

Is this an exact replica of Opta or StatsBomb xG?

No. Commercial models use proprietary data and many more features, including goalkeeper position and defender pressure. This tool is an educational approximation that reproduces the well-known distance and angle relationships, so treat its output as an estimate rather than an official figure.

Soccer Expected Goals (xG) Calculator

Email me this result

Get this tool's output sent to your inbox, plus one useful tool a week. No spam, unsubscribe any time.

Soccer Expected Goals (xG) Calculator

Expected goals (xG) is the most important shot-quality metric in modern football analytics. It converts the location and context of a shot into a scoring probability between 0 and 1. This calculator uses a simplified logistic-regression model to estimate xG from distance, angle, body part, and assist type.

How it works

The dominant geometric driver of xG is the shot angle — the angle subtended at the ball by the two goalposts. With a standard 7.32 m goal, the angle is computed from the shooter’s distance d straight out from goal and horizontal offset x from the goal centre. The model forms a linear score and passes it through the logistic function:

half = 7.32 / 2
angle = atan2(half - x, d) + atan2(half + x, d)
z = b0 + bDist * d + bAngle * angle + adjustments
xG = 1 / (1 + e^(-z))

Distance has a negative coefficient (farther shots are worth less) and angle has a positive coefficient (wider sight of goal raises xG). Headers and one-touch shots from crosses apply negative adjustments, reflecting their lower historical conversion.

Example and notes

A penalty-spot shot (about 11 m out, directly central) opens a wide angle and produces an xG around 0.20-0.25 for an open-play strike. A close-range tap-in from 4 m sits near 0.5-0.7, while a long-range effort from 28 m central drops below 0.05.

Tips: the relationship between distance and xG is steep and non-linear because of the logistic curve — moving from 16 m to 10 m raises xG far more than moving from 30 m to 24 m. Use xG to judge chance quality over a match rather than relying on raw shot counts, since ten low-quality shots can be worth less than one excellent chance.