Several times a year I hear on zero waste facebook groups that washable sanitary napkins are so expensive. But did you have to think about their long-term cost if you divide the purchase cost by the number of uses you will make of them?
The cost of a disposable vs washable sanitary napkin
When you know that a disposable pad costs pennies, it's hard to believe that a washable pad can quickly become cheaper than a disposable pad. 1,2,3 let's go!
A well-priced disposable pad costs about 30 cents each, while a washable pad costs an average of $12.
A woman has an average of 13 menstrual cycles in a year. Many of my customers wash in the middle of their cycle in order to use 2x their towels in each of their cycles. This gives us a total of 26 uses per year.
For one year of use, your towels will have cost you approximately ($12/26 uses) = 46 cents per use. Then, if you use your pads for several years, this figure quickly decreases:
2 years = 52 uses = 23 cents
3 years = 78 uses = 15 cents
4 years = 104 uses = 12 cents
5 years = 130 uses = 9 cents
...
10 years = 260 uses = 5 cents
Are washable sanitary napkins durable enough for 10 years?
Yes! It all depends on how they are maintained. With good care, they will last a very long time.
Cost of maintaining a washable sanitary napkin and water usage
Washable sanitary napkins are never washed alone in the machine. They will be part of one of your washing cycles that you will already be doing. So no additional maintenance cost. You will do your washing as usual!
The trick is to buy one, two or three towels of different designs and try them out before buying a whole lot. It helps to know what you like 
Psssst: Some cities offer subsidies for the purchase of washable sanitary napkins.
Note: The article was written with the prices and knowledge of February 2021.