PEX Tubing Needed
480 ft
Area
300 sq ft
Materials
$1,760
| Spacing | BTU/sq ft | Best For |
|---|---|---|
| 6" | 40 | High heat loss, bathrooms |
| 9" | 30 | Standard rooms |
| 12" | 25 | Well-insulated, supplemental |
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Price as of Jul 24, 2026. Product prices and availability are accurate as of the date indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Inputs
Result
120 sq ft / 0.5 ft spacing = 240 ft. Plus 10% turns (264 ft) + 20 ft header = 284 ft. 1 roll of 300 ft.
Inputs
Result
300 sq ft / 0.75 ft = 400 ft. Plus 10% (440 ft) + 40 ft headers (2 zones) = 480 ft.
Divide your floor area by the loop spacing (in feet), then add 10% for turns and headers. A 300 sq ft room with 9-inch spacing needs about 440 linear feet of PEX tubing plus 20 feet per manifold zone for headers.
Standard 9-inch spacing works for most rooms at 30 BTU/sq ft output. Use 6-inch spacing for bathrooms and high heat loss areas (40 BTU/sq ft), and 12-inch for well-insulated supplemental heating (25 BTU/sq ft).
Materials cost $6–$12 per square foot for a hydronic system including PEX, manifold, insulation, and controls. Professional installation adds $6–$12/sq ft. A 300 sq ft room costs $3,600–$7,200 total.
PEX-A (expansion method) is preferred for radiant floors because it has shape memory and fewer fittings. PEX-B works but is stiffer and harder to bend around tight turns. PE-RT is a newer alternative that can be heat-welded.
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Last Updated: Jul 24, 2026
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