Measure the length of all of the pipes you plan to insulate and write down the total length. Also note the widths, or diameter, of the pipes you will be insulating. Typically, the standard diameter sizes for house pipes are 3/4 inch and 1 inch.
Count the total number of pipe elbows or joints you need to insulate. Write this number down.
Determine the type of pipe insulation you want to use. Foam insulation that wraps snugly around pipes is the most popular and cost-efficient type of pipe insulation on the market. It is typically sold in 6-foot lengths that cost approximately $2. 3/4-inch diameter insulation usually runs about 10 to 20 cents less than 1-inch diameter insulation. For estimating purposes though, round up to $2 per 6-foot length to cover both diameter sizes. Foam elbows, used to insulate U-curves in plumbing and pipes, cost approximately $1 to $1.50 each.
Multiply the total footage of pipe you intend to cover by $2.
Multiply the total number of insulated elbows you will need times $1.50 (or you can round up to $2 each just to be on the safe side).
Add these two totals up and it will give you an approximate value for the insulation costs for your specific job.