Greenhouse, Indoor Farming & Agri-Processing calculator
Water use per crop calculator
Water use per crop tells a greenhouse or controlled-environment grower exactly what it costs to deliver irrigation and process water for one full crop cycle, then breaks it down to a true cost per gallon. Growers running hydroponic, NFT, or substrate systems use it to defend water budgets, justify recirculation or RO retrofits, and load water cost into per-case COGS. Because water and sewer are billed together and treatment runs as a fixed adder, the headline rate per gallon is almost always higher than the utility line item alone. Knowing the blended number is what separates a real cost model from a guess.
What this calculator does
- Estimate total water cost per crop cycle for a greenhouse or indoor farm from gallons used, $/gal water-and-sewer rate, plus fixed RO/UV treatment and labor costs so growers can quote water as a real cost-of-goods line.
- Use it when costing a leafy green or tomato crop, comparing drain-to-waste against recirculating systems, or evaluating an RO or rainwater capture project against current water bills.
- It computes total water cost for one crop cycle and the resulting cost per gallon delivered, separating variable water/sewer from fixed treatment and labor adders.
Formula used
- Total water cost per crop cycle = total water used × blended water and sewer rate + fixed RO, UV, and treatment cost + water-system labor
- Water cost per gallon delivered = total water cost per crop cycle ÷ total water used per crop cycle
Inputs explained
- Total water used per crop cycle:
- Blended water and sewer rate:
- Fixed RO, UV, and treatment cost per cycle:
- Water-system labor per cycle:
How to use the result
- Use it when budgeting a crop cycle, comparing recirculating versus single-pass irrigation, or pricing water into finished-product cost.
- It assumes a flat blended water/sewer rate; tiered utility pricing, seasonal surcharges, or stormwater fees can push the real rate above the figure shown.
Current U.S. benchmarks
- U.S. housing starts run at 1,177k per year (Census, May 2026), down 8.7% from a year earlier, the demand driver for building products.
- Industrial natural gas averages $4.9 per Mcf (EIA, Apr 2026), down 7.7% from a year earlier, with industrial electricity at 8.66 cents per kWh. Process heating and refrigeration budgets track both.
Common questions
- How do you calculate water cost per crop cycle? Multiply total water used by your blended water and sewer rate, then add fixed RO/UV/treatment cost and water-system labor. With 12,000 gal at $0.012/gal plus $75 treatment and $60 labor, the total is $279 per cycle.
- What is the cost per gallon of treated greenhouse water? Divide total cycle cost by gallons used. In the example $279 over 12,000 gal works out to about $0.0233 per gallon delivered, well above the $0.012 raw utility rate because treatment and labor are folded in.
- Why is my delivered water cost higher than the utility rate? Fixed adders. The $75 treatment and $60 labor add $135 per cycle regardless of volume, so at lower gallons the per-gallon cost climbs sharply while the utility rate stays flat.
- Does recirculation actually lower water cost per crop? It lowers the variable water/sewer portion (here $144) but not the fixed treatment and labor adders, so payback depends on how many gallons you avoid buying and discharging versus added pump and dosing labor.
- Should sewer charges be included in the blended rate? Yes. Most municipalities bill sewer as a function of metered water, so a true blended rate combines both; leaving sewer out understates delivered cost by a third or more in many districts.
Last reviewed 2026-05-12.