How to Use Pool Salinity Calculator
The Pool Salinity Calculator estimates how much pool salt is needed to raise a saltwater pool from the current ppm reading to a target ppm. It supports gallons, liters and cubic meters so you can work from pool-builder specs or metric water volume.
- Enter pool volume — gallons, liters or m³.
- Enter current ppm — from a salt tester or strip.
- Enter target ppm — usually 2700–3400 for saltwater chlorinators.
- Pick the salt unit — kg, lb or bags (and bag weight).
- Read salt to add — spread slowly with the pump running.
Formula & Theory — Pool Salinity Calculator
The Pool Salinity Calculator only adds salt when the target is above the current reading. Parts per million is a mass ratio, so a 1000 ppm increase means 1000 mg of salt per liter of pool water.
saltDelta = target_ppm - current_ppm
// In a liter-based pool
salt_kg = volume_L × saltDelta / 1,000,000
// In a gallon-based pool
salt_lb = volume_gal × saltDelta × 0.00000834
bags = salt_weight / bag_weightAssumptions and Limits
The calculation assumes pure pool salt and a well-mixed pool. Test strips can be imprecise, and salt chlorinators often have their own preferred range. If current ppm is above target, the calculator will not recommend adding salt; partial drain-and-refill is the usual correction.
Use Cases for Pool Salinity Calculator
The Pool Salinity Calculator is useful for:
- Spring opening — Bring a saltwater pool back to the chlorinator range.
- Rain dilution — Correct low ppm after storms or partial draining.
- Backwash recovery — Estimate salt replacement after filter maintenance.
- Commercial ordering — Convert many pools into bag counts for purchasing.
After adding salt, brush the pool floor and circulate at least 24 hours before retesting.