Salt water boils at a higher temperature than regular water, so it will take faster for the saltwater to come to a boil than regular water. However, the amount of time it takes for saltwater to boil will depend on how much salt is in the water and the size of the pot or pan.
Saltwater still has a higher boiling point than fresh water, and adding salt to water increases its mass, so saltwater does not necessarily boil faster.

It would take a lot of salt to make a significant difference.
So to answer your question of how long it takes for salt water to boil? The answer is, not that much different than regular water.
Does salt water take longer to boil?
Adding salt to water does raise the boiling point marginally, so it will make your water hotter. However, the salt added is too low to make a noticeable difference in your cooking time.
Why does salt in water make it boil faster?
Put simply, saltwater heats up faster but has to get to a higher temperature to boil (which takes longer). Saltwater requires less energy to heat up but must be heated to a higher temperature to boil. But to see an actual difference, you need A LOT of salt, which we don’t recommend you use.
Why do people add salt to the water?
There are two primary reasons to add salt to water: to improve the flavor of food cooked in it and to help it boil (slightly) faster. While salting water does raise the boiling point, the difference is so insignificant that it doesn’t affect cooking time.
The different variables that can affect the boiling time of salt water
The boiling time of salt water can be affected by various variables, including the type and amount of salt used, the size and shape of the pot or pan, the temperature of the water, and how much water is being boiled. In general, it takes longer to boil salt water than fresh water.
One way to speed up the boiling time of salt water is to add a small amount of baking soda. This will help break down some of the molecules in the water and make it easier for them to escape as steam. Another method is to heat your pot or pan before adding any liquid; this will help prevent heat loss once you add your ingredients.
Does Baking Soda Warm Water?
A common question is whether adding baking soda to water increases the temperature. The answer is that it only increases the temperature slightly. This is because baking soda and water have an exothermic reaction. When baking soda mixes with water, an exothermic reaction takes place. The chemical bonds of each product bind and release energy. This energy then causes the temperature of the water to rise, although not by much.

Jay
Self assessed Germaphobe, specializing in everything water, water filters, health and nutrition. Diagnosed with Type 2 Diabetes, I've acquired immense amount of knowledge when it comes to natural, biology, and everything about human anatomy.