Dosing Calculator

IMPORTANT: Please note when using any of the dosing calculators that they are only a guide. Swimmingpoolchemicals accepts no responsibility for any damage.

Pool chemical dosing is an essential factor in keeping your pool water in balance and in excellent condition. Knowing the amount of chemicals required to correctly dose your pool can be tricky, so why not use our swimming pool volume calculators to help you out.

Once you know the rough volume of your pool, you can use our set of calculators to help estimate various dosing rates for the most common pool water problems.

You’ll need some testing strips to know the chemical concentration in your pool and keep them at the correct level.

How to find the right chlorine dose for your pool

Start by calculating the volume of water in your pool using our Pool Water Volume Calculator. Just enter the dimensions of your pool (in metres) and the calculator will work out the approximate volume of your pool (a metric converter is provided to aid you with this).

Following this, you can use the chlorine dosing calculators to work out the required chemical dose to increase the amount of chlorine in the water.

How much chlorine in a pool is required?

The amount of chlorine in the water should be somewhere between 1 and 3ppm (parts per million).

So, if you’re starting with completely clean unchlorinated water, then you can set the dosing calculator to a ppm within that range, enter how many litres of water are in your pool, and our calculator will tell you the required amount of stabilised chlorine granules to add.

How much chlorine in a hot tub is required?

It’s recommended that you keep the chlorine levels within a hot tub between 2 and 4 ppm in order to keep it sanitised.

Again, you can use our chlorine shock dose calculator to help you figure out how that translates into the amount of chlorine granules required for your hot tub size.

How do you adjust pH levels?

When adjusting pH levels, there aren’t any reliable dosing calculators for pH levels available.

This is due to the fact that other factors such as alkalinity also affect the pH

We advise you to obtain a correct level of total alkalinity (70-160 p.p.m) and then add small quantities of pre-dissolved pH Increaser (Sodium Carbonate) or pH Reducer (Sodium Bisulphate).

Once this has circulated for 24 hours, you can retest the water to find the pH level. The ideal range for pH is 7.2-7.6 p.p.m. If your water isn’t within this range, continue to use the pH Increaser or pH Reducer, circulate for 24 hours, and retest until you come away with a passing test result.


1 - Rectangular Pool
 Length  metres
 Width  metres
 Depth (deepest)  metres
Depth (shallowest)  metres
Volume ,000 litres


2 - Trapezoidal Pool
Length (short) metres
Length (Long) metres
Width metres
Depth (deepest) metres
Depth (shallowest) metres
Volume: ,000 litres


3 - Round Pool
Diameter metres
Depth (deepest) metres
Depth (shallowest) metres
Volume: ,000 litres


4 - Oval Pool
Length metres
Width metres
Depth (deepest) metres
Depth (shallowest) metres
Volume: ,000 litres


Convert Gallons to Litres
Volume in Gallons  
Volume is equal to litres  or m3


Convert Litres to Gallons
Volume in Litres  
Volume is equal to Gallons



To increase chlorine using
Stabilised Chlorine Granules (Ideal Range: 2 - 4ppm)
Desired increase in chlorine
Volume of the pool ,000 litres
grams of Stabilised Chlorine Granules are required


To reduce total alkalinity using
pH Reducer (Dry Acid - Sodium Bisulphate) (Ideal Range: 100-160 ppm)
Desired reduction in total alkalinity
Volume of the pool ,000 litres
grams of pH Reducer (Dry Acid - Sodium Bisulphate) are required


To increase total alkalinity using
Alkalinity Builder (Sodium Bicarbonate) (Ideal Range: 100-160 ppm)
Desired increase in total alkalinity
Volume of the pool ,000 litres
grams of Alkalinity Builder (Sodium Bicarbonate) are required


To increase calcium hardness using
Calcium Builder (Calcium Chloride) (Ideal Range: 75-150 ppm)
Desired increase in calcium hardness
Volume of the pool ,000 litres
grams of Calcium Builder (Calcium Chloride) are required