Two free planning calculators for waterproofing projects. The first turns area, thickness and solids content into gallons of primer and membrane. The second compares two or three roof systems on cost per square foot per year, which is a fairer comparison than installed price alone. Both run in your browser and send nothing anywhere.

Calculator

Waterproofing Material Quantity Calculator

Enter the area, the specified dry film thickness and the product's volume solids from its data sheet.

Math: one gallon (231 cubic inches) of 100% solids material covers 1,604 sq ft at 1 mil dry. Coverage = 1,604 × solids ÷ mils. Waste covers overspray, surface texture, hose flushing and touch-ups; spray work on rough concrete often needs more than smooth roll-applied work. Primer coverage varies with porosity. Always confirm with the product data sheet before ordering.

Comparison

Roof System Lifetime Cost Comparison

Enter installed cost, expected service life and yearly maintenance for up to three systems. Leave a system's cost at 0 to skip it.

The default values are illustrative placeholders, not price quotes or performance claims. Replace them with your contractors' bids, the warranty terms offered and your own maintenance history. Cost per sq ft per year = installed cost ÷ expected life + annual maintenance. The analysis-period total simply multiplies that yearly cost by the area and years; it ignores inflation, financing, tear-off of the old roof, energy savings and leftover service life.

How to use these numbers

The quantity calculator is only as good as its inputs. Take the thickness from the manufacturer's system specification for your warranty term, and the volume solids from the product data sheet, not the marketing brochure. A 100% solids polyurea at 60 mils needs far less material than a 60% solids water-based coating at the same dry thickness, because the water evaporates. The wet film figure tells your crew what to read on a wet film gauge as they apply.

Waste is real. Spray application loses material to overspray, wind, hose flushing and the texture of rough concrete. Small, cut-up areas with many details use more per square foot than large open fields. If you are unsure, compare your estimate with actual usage on the first day and adjust.

For the lifetime comparison, use expected service life you can defend: the warranty term offered, or your own experience with similar roofs. A coating that is cheap today but needs recoating twice as often may cost more over 30 years, while an expensive membrane on a building you plan to sell in five years may not pay back. The tool shows how many installations each system would need over your analysis period so you can see that effect directly. Before choosing, read our honest roof membrane comparison and check whether your roof is a good restoration candidate.

Not a quote

These tools are planning aids. Material ordering, warranty eligibility and budgets should be confirmed with the manufacturer and a qualified installer for your specific project.

Frequently asked questions

Why does solids content matter so much?

Only the solids remain after the coating cures. A 50% solids product must go on at twice the wet thickness to reach the same dry thickness, which doubles the gallons needed compared with a 100% solids product.

What waste percentage should I use?

Many estimators start around 10–15% for roll-applied work on smooth surfaces and more for spray work, rough concrete, wind or highly detailed areas. Track actual usage to refine it.

Does the lifetime cost tool include tear-off?

No. Add tear-off, insulation and disposal to the installed cost of any system that requires them, so the comparison stays fair.

Can I use these calculators for floors and decks?

Yes. The quantity calculator works for any coating specified by dry film thickness and volume solids, including deck coatings and pond linings.