How do I measure the corner radius of my pool?
Square the corner, then measure from where the curve starts to where the two straight walls would meet. Double-check the result against your straight walls, the arc, or the chord.
When you measure for a replacement liner, squaring the corners gives you a common reference point for your length, width, and diagonal measurements, and lets you find the corner size.
How to measure the radius
- Extend each straight wall past the corner until the two lines meet. Snapping a chalk line is an easy way to do this.
- Find where the curve starts, the point where the straight wall ends.
- Measure from that point to where the two lines meet. That distance is your corner radius.
If you plan to use the arc or chord checks below, measure in inches.
Check your measurement
| Check | What to measure | It should equal | Example |
|---|---|---|---|
| Straight wall | The straight section of wall between two corners | The full side length minus two times the radius | 16' x 32' pool with 2' radius corners: 32' − 2' − 2' = 28' on the long sides, 16' − 2' − 2' = 12' on the short sides |
| Arc | Around the curve, using a flexible tape | Radius in inches × 1.5708 | 30" radius: about 47.12" |
| Chord | Straight across the curve, from where it starts on one wall to where it starts on the other | Radius in inches × 1.4142 | 24" radius: about 33.94" |
If a check does not match, re-measure the radius. The arc factor, 1.5708, is a quarter of a circle's circumference (2 × π ÷ 4).
These checks work for rounded corners where the two walls meet at a right angle, as on a rectangle pool. For corners at other angles they will not give the right result.
Learn more
- Help! How Do I Measure the Corner Radius of My Pool? has photos of each method and a chart of common corner sizes.
- How to AB Measure a Pool for a New Liner
- How do I measure swimming pool for safety cover?
- Ordering a replacement safety cover
- Inground pool liners
Still need help?
Didn't find the answer you were looking for? You can always contact us at support@royalswimmingpools.com or choose the category below to see our most frequently asked questions for that topic: