Write down the cost of the camera that you'll film the movie with, if you do not already have one.
Break down each scene in the movie, listing the actors, location, equipment and crew that is needed to shoot each scene, using the movie's screenplay. List what days you will shoot each specific scene, according to the availability of the cast and crew, to create a shooting schedule.
Obtain equipment rental quotes and list the costs of all the equipment you need, such as lighting and sound equipment. Follow the shooting schedule to know which days you need specific rental equipment.
List all the crew you need, along with the cost of each member. Remember to include the crew needed for post-production, as well.
List the pay for each specific actor you need. List the estimated daily costs of transportation and food for the cast and crew, following the shooting schedule.
Comb through the screenplay, page by page. Write down all elements that you do not have free access to, such as specific locations, props and vehicles. List the items, along with the estimated cost of purchasing or renting each one.
List the estimated cost of editing the movie, depending on whether you have the software to do it yourself, or you will enlist outside services.
Add up all the listed costs, using a calculator.