Home / Gann Square of Nine calculator
Enter one price. Get the prices that sit at fixed angles from it on Gann's spiral. Free, in your browser, no account.
A Gann Square of Nine calculator converts a price into an angle on a number spiral, then lists the other prices that sit at 45 degree steps from it. The rule is simple: square root the price, add 0.5, 1 or 2 for a quarter, half or full turn, and square the result. The calculator below does that for several rings at once.
Worked example, anchor 85.40. It sits at 43.4 degrees on the spiral. 48 levels are generated at a 45 degree step over 4 rings. These are the 16 closest to the anchor:
| Price | Distance | Axis | Angle | Ring |
|---|---|---|---|---|
| 52.56 | -38.45% | diagonal (NE) | 45° | -1 |
| 56.25 | -34.13% | cardinal (North) | 90° | -1 |
| 60.06 | -29.67% | diagonal (NW) | 135° | -1 |
| 64.00 | -25.06% | cardinal (West) | 180° | -1 |
| 68.06 | -20.30% | diagonal (SW) | 225° | -1 |
| 72.25 | -15.40% | cardinal (South) | 270° | -1 |
| 76.56 | -10.35% | diagonal (SE) | 315° | -1 |
| 81.00 | -5.15% | cardinal (East) | 0° | 0 |
| 85.56 | +0.19% | diagonal (NE) | 45° | 0 |
| 90.25 | +5.68% | cardinal (North) | 90° | 0 |
| 95.06 | +11.31% | diagonal (NW) | 135° | 0 |
| 100.00 | +17.10% | cardinal (West) | 180° | 0 |
| 105.06 | +23.02% | diagonal (SW) | 225° | 0 |
| 110.25 | +29.10% | cardinal (South) | 270° | 0 |
| 115.56 | +35.32% | diagonal (SE) | 315° | 0 |
| 121.00 | +41.69% | cardinal (East) | 0° | +1 |
Change the anchor and press Calculate levels to run your own price. With JavaScript off, the table above stays as a fixed example.
Two formulas do all the work. The first converts a price to its angle on the spiral. The second converts a ring and an angle back to a price.
| Rotation from the anchor B | Resulting price | For B = 85.40 |
|---|---|---|
| 90°, a quarter turn | (√B + 0.5)² | 94.89 |
| 180°, a half turn | (√B + 1)² | 104.88 |
| 360°, a full turn | (√B + 2)² | 126.36 |
The browser calculator uses the same arithmetic as the Crohamhurst app, and the two have been checked against each other across 42 anchor, step and ring combinations. Other calculators start the spiral at a different value or use a different angle convention, so their numbers can differ from these. If you compare them, check one known case first: from 100, a half turn (180 degrees) lands on 121.00 here.
It does not predict a turn, rank levels by likelihood or give trading advice. Crohamhurst has not tested whether Square of Nine levels behave differently from other prices. It is a geometry tool. Trading carries risk of loss.
The Gann Square of Nine is a spiral of numbers that starts at 1 in the centre and winds outwards. W.D. Gann traders use it to relate a price to an angle, then read off other prices that sit at fixed angles from it, which they treat as possible support and resistance levels.
Take the square root of the anchor price, add 0.5 for a 90 degree move, 1 for 180 degrees or 2 for a full 360 degree turn, then square the result. For an anchor of 85.40, a half turn gives (sqrt(85.40) + 1)^2 = 100.00.
Yes. This page runs in your browser, needs no account and sends nothing to a server. The full Crohamhurst app adds a spiral chart, CSV export for 25 instruments, and the other Gann and planetary cycle modules, with a free plan of 50 compute units a day.
No. It is a geometric calculator. It returns the prices that sit at fixed angles from your anchor. Crohamhurst has not tested whether those levels behave differently from any other set of prices, so treat them as reference marks, not forecasts.
Most users anchor on a significant swing high, swing low or the current price. The anchor dominates the result, so a different anchor gives a different set of levels. Use the same price units every time, because the square root of a price is not scale invariant.
The full app draws the spiral wheel, exports CSV for 25 instruments and adds the Bradley siderograph, planetary ephemeris, cycle scanner and historical analogs. The free plan includes 50 compute units a day and needs no card.