Choose the correct measuring device for the area that you wish to measure. A trundle wheel (also known as a measuring wheel) is suitable for large square areas such as a field, playground or road, while a laser measurer provides quick lengths for indoor walls.
Figure out how to use the tool you have chosen to measure with. For example, if you are using a measuring wheel, practice pacing forward and counting the wheel's rotations. If you are using a measuring tape, decide whether to measure in inches or centimeters.
Draw a rough diagram of the space you want to measure. Use a blank piece of paper to illustrate the area's approximate shape so you can annotate it with your measurements.
Use your measuring device to measure the area. Every time you take a measurement write it down in the corresponding place on your diagram. That way, you will not forget what each measurement relates to.
Draw more diagrams if you are measuring interior surfaces. Because one two-dimensional image will not be sufficient to illustrate ceiling, wall, floor and door areas, you will need to create separate diagrams for each surface. Note the measurements on the images accordingly.
Calculate the area of each surface. Do this by multiplying the length and width of each area that you measured. This will give you the surface area.