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Pool & Spa Peroxide Calculator
Calculate exactly how much hydrogen peroxide you need to reach a safe sanitizing or shocking PPM level for your pool or spa.
Your starting product concentration
Target PPM (parts per million)
Or calculate from pool dimensions
Your Result
Hydrogen peroxide needed—
Pool volume—
Target PPM—
Add the calculated amount while the pump is running. Retest after 4 hours. Safe to swim when PPM drops below 100.
Pool Size Reference Chart
| Pool size | Volume (gal) | 12% @ 50 PPM | 12% @ 100 PPM |
|---|---|---|---|
| 12 × 24 ft oval | 6,400 | 0.85 gal | 1.70 gal |
| 14 × 28 ft rect | 8,100 | 1.07 gal | 2.14 gal |
| 16 × 32 ft rect | 10,000 | 1.32 gal | 2.64 gal |
| 18 × 36 ft rect | 13,600 | 1.80 gal | 3.59 gal |
| 20 × 40 ft rect | 19,200 | 2.54 gal | 5.07 gal |
| 250 gal spa | 250 | 4.2 fl oz | 8.5 fl oz |
Safety Notes
- Wear gloves and eye protection when handling 35% or 12% concentrate.
- Never mix hydrogen peroxide with chlorine — hazardous gas can form.
- Do not enter the pool until PPM drops below 100.
- Store in a cool, dark location away from sunlight.
- Always dilute 35% concentrate before adding to pool water.
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