Pool Salt Calculator

Enter your pool gallons and current and target salt levels to get the pounds of salt and number of 40 lb bags needed.

How to use this calculator ↓

What your result means

This is the pool-grade salt to raise your level from current to target, plus the number of 40 lb bags to buy. Most chlorinators want 3,000 to 3,500 ppm. Add it gradually with the pump running and brush any undissolved salt off the pool bottom, since over-salting can only be fixed by draining and diluting.

How to use this calculator

  1. Get pool gallons from pool volume calculator.
  2. Test current salt level with strips or kit.
  3. Target: 3000-3500 ppm for most saltwater chlorinators.
  4. Read pounds of salt needed and number of 40 lb bags.
  5. Add salt directly to pool, brush to dissolve.

The formula

lbsNeeded = gallons * (targetPPM - currentPPM) * 8.345 / 1,000,000 bags = ceil(lbsNeeded / 40)

The salt needed is the pool gallons times the ppm increase times 8.345, divided by a million. Divide by 40 and round up for the number of bags.

Worked example

Say you've got a 15,000 gallon pool at 2,000 ppm and you're targeting 3,200. That's a 1,200 ppm bump, about 150 lbs of salt, or 4 bags of 40 lb.

Saltwater pool levels

Levelppm
Target range3,000 – 3,500
Typical setpoint3,200
Corrosive (too high)over 6,000

Tips & gotchas

  • Most chlorinator systems target 3,000 to 3,500 ppm.
  • Test the salt level monthly.
  • Add salt gradually; over-salting means draining and diluting.
  • Add it with the pump running.
  • Brush undissolved salt so it doesn't damage the pool bottom.

Frequently asked questions

How much salt do I need for my pool?

Use the calculator. A first fill on an average pool is usually 200 to 400 lbs.

What's the right salt level?

3,000 to 3,500 ppm for most chlorinators. Check your unit's spec.

Can I use regular table salt?

No. Use pool-grade salt, which dissolves cleanly.

How long does pool salt last?

Salt isn't used up, but rain and splashout dilute it, so test monthly.

Will too much salt damage my pool?

Over 6,000 ppm gets corrosive to equipment.

Related calculators

Estimates only — see our full disclaimer.