Gann Angles

What they are

Gann angles are a technical analysis tool created by W.D. Gann that relate price movement to time using fixed geometric slopes. A set of these angles (a Gann fan) is drawn from a significant high or low to help gauge trend strength and potential support/resistance as price moves through different slopes.

Core concept

The central angle is the 1:1 (one price unit per one time unit), commonly represented as a 45° line. Gann considered this the ideal balance of time and price.
Other standard ratios include 8:1, 4:1, 3:1, 2:1 (steeper than 1:1) and 1:2, 1:3, 1:4, 1:8 (shallower). Some practitioners also use 16:1 and similar variations.
Interpretation: If price stays above an ascending angle, the trend is considered strong; if it stays below a descending angle, the trend is weak. When price breaks one angle, it may move toward the next angle—but not always.

How they’re defined and scaled

A ratio X:Y means X price units for every Y time units (e.g., 3:1 = three price units per one time unit; 1:3 = one price unit per three time units).
You can choose the unit sizing to fit the market (e.g., for the S&P 500, defining 10 or 30 index points per time unit as the 1:1 line is common). The key is consistency.
Lock the chart scale. Most platforms auto-scale when zooming; that alters the visual angle and changes where angles intersect price/time. Locking prevents that distortion.

How to use Gann angles

Draw a Gann fan from a clear swing low (for potential rising angles) or swing high (for descending angles).
Observe which angle the price respects:
Remaining above an ascending angle suggests sustained strength.
Breaking below an ascending angle can signal weakening and a potential move to the next lower angle.
The same logic applies in reverse for downtrends.
Use angles for context on trend strength and possible areas of support/resistance, not as isolated entry/exit signals.

Example (conceptual)

From a meaningful low, draw the 1:1 (45°) and the additional Gann angles. If price initially follows a steep angle (e.g., 3:1) and later slips below it, the market may start respecting a shallower angle (e.g., 2:1 or 1:1). You can also apply descending fans from highs to track developing downtrends.

Difference from trendlines

Gann angles are fixed geometric slopes based on set price/time ratios and do not adjust to connect specific price swings.
Trendlines are drawn to connect swing lows or highs and follow the actual price path. They convey different types of information: Gann angles express predefined rate-of-change relationships; trendlines reflect recent price action.

Limitations and practical cautions

Subjectivity: Because chart scales vary, two traders can draw different Gann angles on the same instrument unless they use identical scaling and ratio definitions.
Not a reliable standalone signal: Prices often do not move cleanly from one angle to the next; many breakouts or breakdowns fail or produce whipsaws.
Tool sensitivity: Auto-scaling, different timeframes, and chosen units affect where angles fall. Lock scale and document your ratio choice before analysis.

Practical tips

Decide and document the price/time unit that defines your 1:1 line for each market.
Lock chart scaling to preserve angle geometry.
Use Gann angles alongside other technical tools (support/resistance, volume, momentum) to confirm signals and reduce false interpretations.

Conclusion / Key takeaways

Gann angles offer a geometric way to frame trend strength by comparing price change against time.
The 1:1 (45°) angle is central; other ratios indicate steeper or shallower trends.
They provide useful context but are subjective and should not be used as sole trade triggers. Use consistent scaling and combine with other analysis methods.