How to Measure Your Pool for a Cover
A 7-step guide to getting accurate measurements for a perfect fit
Accurate pool measurements are the difference between a pool cover that fits perfectly and one that's expensive to remake. Whether you're getting a quote, ordering a DIY thermal blanket, or just want to understand the process, this 7-step guide walks you through how a professional installer measures a pool — and how you can do it yourself.
What You'll Need
30-metre tape measure (a regular 5 m DIY tape will not work)
Notebook + pen, or a phone with a notes app
A second person to hold the tape — measuring alone is hugely error-prone
A camera or phone — photograph the pool from 3 angles after measuring
Step 1 — Measure the Maximum Length
Run the tape along the longest edge of the pool, from the outermost point of one end to the outermost point of the other. Always measure the OUTSIDE edge of the coping if you want a cover that overlaps the rim, or the INSIDE edge if you want a cover that drops into the water. Record to the nearest 10 mm. A measurement of 8.43 m is more useful than 8.4 m.
Step 2 — Measure the Maximum Width
Run the tape perpendicular to the length, at the widest point. For rectangular pools this is straightforward. For free-form pools, take measurements at multiple points along the length.
Step 3 — Handle Roman-End and Free-Form Pools
Roman-end pools: measure to the outermost point of the curved end, not the start of the curve. Free-form / kidney pools: a professional measurement is mandatory — DIY is not reliable for irregular shapes. Lap pools: measure twice along the full length to confirm consistency.
Step 4 — Rim-Flow and Vanishing-Edge Pools
Rim-flow pools have water flowing over one or more edges into a balance tank. The cover must terminate at the OPPOSITE side of the rim flow. A professional measurement is mandatory for these pool types.
Step 5 — Photograph the Pool
Take photos from: directly overhead (drone or upstairs window), from each end, and a close-up of the coping detail. Send these with your measurements when requesting a quote.
Step 6 — Note Any Obstacles
Steps protruding into the pool, water features, ladders, in-pool benches, lights, skimmer baskets — all affect cover design. List each by location.
Step 7 — Decide on Cover Overlap
Most thermal blankets are sized to the exact water surface (no overlap). Safety covers typically include a 200–300 mm overlap onto the deck for tensioning. Specify your preference when ordering.
Common Mistakes to Avoid
Measuring with a 5 m tape: joining sections introduces error. Use a 30 m tape or a proper laser distance meter.
Measuring alone: tape sag introduces 50–100 mm error per measurement.
Rounding to the nearest 100 mm: always record to 10 mm precision.
Ignoring the coping detail: overlap-style covers need different measurements than drop-in covers.
When to Call a Professional
Free-form pools, Roman-end pools, rim-flow pools, vanishing-edge pools, and any pool over 10 m in length should be professionally measured. Designer Pool Covers offers a free on-site assessment that includes laser-precise measurement, design recommendation and quote — no obligation.
Frequently Asked Questions
Can I measure my pool myself for a quote?
Yes — for rectangular pools, your measurements are accurate enough for a budgetary quote. The final cover is always re-measured by our installer before manufacturing.
How long does professional measurement take?
30–45 minutes for a standard pool, including consultation.
Is the on-site measurement free?
Yes — Designer Pool Covers offers free on-site assessment with no obligation.
Willem de Wet
Founder & Managing Director, Designer Pool Covers
Willem founded Designer Pool Covers in 2012 and has personally overseen 4,500+ installations across South Africa. NSPI accredited and SABS SANS 10134:2016 certified.
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