Sum up all the fixed expenses that you will have to bear every month. Fixed expenses could include salary of any paid employees, insurance and business loans, maintenance, cleaning and supplies expenditures and of course the rent of the building. Let us assume that the monthly rent is $2,000, the cost of maintenance, cleaning and supplies is $1,000, insurance and business loans amount to a total of $1,000, total salary of paid employees is $2,000 and you have to spend $1,000 for other services, the total fixed expense would be $7,000 every month.
Now it comes to calculating the total monthly variable expenses such as electricity, sewerage, water and gas bills. These expenses vary depending on the amount of each service or product used. Refer to the utility bills in order to estimate these expenses. For instance, if the monthly electricity bill is $800, the amount of monthly water and gas bills is $700 and the sewerage bill every month is $500, the variable expenses every month would be $2,000.
Calculate the operational cost of the Laundromat by adding up fixed expenses and variable expenses, which in this case will be $9,000.
Calculate the total income by summing up income from all the services that you offer at the Laundromat. For example, if you earn $10,000 from washing machines every month and another $3,000 from an attendee's ironing service, the total income will be $13,000.
To calculate the profit, simply deduct total expense from the total income which in this case will be $13,000 - $9,000 = $4,000.