Termite Foam Calculator: void volume to finished foam, dilution and concentrate
Enter void dimensions or a count of voids, your measured expansion ratio and the label dilution rate to get finished foam volume, liquid dilution volume and concentrate needed. No signup.
How this is calculated
The foam fills the void, so the void volume in cubic feet converts straight to gallons of finished foam (1 ft³ = 7.48052 US gal). The expansion ratio divides that foam volume back down to the liquid dilution you actually mix: a 10:1 ratio means 10 gallons of foam per gallon of liquid. The label dilution rate then tells you how much concentrate goes into that liquid.
Dimensions mode:
void_ft³ = length × width × depth
Count mode:
void_ft³ = number_of_voids × volume_per_void
All modes:
foam_gal = void_ft³ × 7.48052
dilution_gal = foam_gal / expansion_ratio
concentrate_floz = dilution_gal × label_rate_floz_per_gal
With buffer:
dilution_gal_buf = dilution_gal × (1 + buffer)
concentrate_buf = concentrate_floz × (1 + buffer)Finding your expansion ratio: Dr Bob Davis, BCE, writing in Pest Management Professional (September 2019), directs operators to "review the termiticide label, the foaming agent manufacturer's directions, and the foam-generating unit manufacturer's directions for further guidance." Measure the ratio on your own rig before every job rather than relying on a published range.
Published context on expansion ratios: Dr Bob Davis, BCE, writing in Pest Management Professional (September 2019), classifies wet foams at less than 3:1, medium foams at 6:1 to 10:1, and dry foams at 25:1 to 50:1. Those ranges describe the industry spectrum, not a recommendation for your job. Your product label and foaming agent directions govern; this tool takes whatever ratio you enter.
This tool sizes one void or a batch of identical voids. It does not cover trench-and-treat jobs. The termite trench gallons calculator handles that arithmetic, and the termiticide concentrate yield calculator rolls a bottle up to finished gallons, coverage and bottles needed. For general pesticide dilution math (mixing any concentrate to a target percentage), see the pesticide dilution calculator. Dust sizing for a void that gets dust instead of foam is in the wall void insecticide dust quantity calculator.
You have a foaming rig, a bottle of liquid termiticide and a wall void you need to fill, and the question many labels leave unanswered is: how many gallons of liquid dilution do you actually mix? Many labels give the concentrate rate (fluid ounces per gallon) and say to foam the void until it is full, but they do not tell you how much liquid that takes, because the answer depends on your expansion ratio. This calculator closes the gap. Enter the void volume (dimensions or a count of voids), your expansion ratio from the foaming agent or foam unit manufacturer’s directions, and the label dilution rate, and the tool returns the finished foam volume, the gallons of liquid dilution to mix, and the fluid ounces of concentrate to measure.
Foam sizing sits between two neighbors on this site. The termiticide concentrate yield calculator works the other direction: it starts with a bottle of concentrate and tells you how many finished gallons it makes and how much trench it covers. The termite trench gallons calculator sizes a liquid barrier in the soil, which is a different job from foam in a void. The insecticide dust quantity calculator handles the same void geometry but for dust rather than foam. And the pesticide dilution calculator covers general pesticide dilution math for any concentrate mixed to a target percentage.
The pesticide dosing hub maps Fieldwynn’s dosing and dilution calculators by method. The termite WDO treatment hub maps the full termite sizing and pricing suite.
Everything runs in your browser: no account, no email gate, nothing stored or sent. The tool is a planning aid, not a compliance record. Verify every number against the product label before you mix.
Sources
- Foaming for termites (expansion ratio ranges: wet <3:1, medium 6-10:1, dry 25-50:1). Pest Management Professional (Dr Bob Davis, BCE). Retrieved .