The back contains 7 scales of the following types:
| Type (click to view scale details) |
Range & Units | Numbered | Geometry | Location |
|---|---|---|---|---|
| Altitude | 0 - 90, Degrees | Every 10 degrees | Circular, concentric | The entire outer circle on the back of an astrolabe. |
| Zodiacal signs | 0 - 30, Zodiacal divisions, equal or unequal | Every 10 | Circular, concentric | Circular scale immediately inside the outer scale - refers to the full circle |
| Calendar | First day of month - Last day of month, Days of year | Every 10 days | Circular, concentric | Circular scale second in from the outer scale - refers to the full circle. |
| Unequal hours | 1/12 of daylight | Not numbered hours | Arc | Upper right quadrant (inside circular scales) |
| Shadow square | 0 - 12, Fingers | Every 3 fingers | Box | Left hand vertical 'face' of the shadow square (in LL) |
| Shadow square | 0 - 12, Fingers | Every 3 fingers | Box | Right hand vertical face of the shadow square (in LR) |
| Shadow square | 0 - 12, Fingers | Every 3 fingers | Box | Left hand bottom face of the shadow square (in LL) |
| Shadow square | 0 - 12, Fingers | Every 3 fingers | Box | Right hand bottom face of the shadow square (in LR) |
| Sine/Cosine | 0 - 60, 1/60 of quadrant radius | Every 10 | Linear | The upper two quadrants of the back of the instrument |