Antifreeze Concentration Calculator

Calculate antifreeze solution concentration for sprinkler systems based on minimum temperature.

Input Parameters

Results

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Required Concentration
% by volume
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Antifreeze Volume Needed
gallons
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Water Volume
gallons
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Solution Specific Gravity
Note: NFPA 13 (2022 edition) limits new antifreeze systems to glycerin only, max 50% concentration. Propylene glycol is no longer permitted in new installations. Existing propylene glycol systems may be maintained. Specific gravity must be tested annually per NFPA 25.

Reference

NFPA 13 Table 10.5.3.3 - Antifreeze Solutions: Glycerin: 40% at 20F, 50% at 0F, 60% at -30F Propylene Glycol: 30% at 20F, 38% at 0F, 50% at -30F Antifreeze Vol = System Vol × (Concentration / 100) Note: Glycerine solutions must not exceed 50% by volume per 2022 NFPA 13