Most everything you estimate requires a waste factor. Adding waste factors helps make sure customers have enough material to complete a job.

A waste factor is a percentage of material over the actual estimated, raw quantity. Most applications required a 5% waste factor – but check product recommendations to be sure.

To estimate a 5% waste factor:

Initial Estimated (Raw) Quantity = 46 units
46 X .05 = 2.3 Units
46 + 2.3 Units = 48.3 Units
Quantity Written on Estimate = 49
(round up to selling unit)

There are a number of ways to add waste factors. The easiest is to use the percent key on your calculator to multiply the raw, estimated quantity by the whole plus the waste factor. Since we’re dealing with percents, the whole is always 100% or 100.

To add a 5% waste factor (WF) to a Raw Quantity (RQ):

RQ x (100% + WF%) = Estimated Quantity
46 x (100% + 5%) = Estimated Quantity
46 X 105%=48.3 (Estimate 49)

Be sure to use your percent key on your calculator. If you don’t have a percent key, multiply the raw quantity times 1.05 instead.