Nutrient Cost per Gallon Calculator
Work out what your nutrients really cost. Enter the price, bottle size and dose for each part, and see the cost per gallon, per litre and per reservoir.
How the calculation works
Each part costs its price per millilitre times the millilitres you use. Add the parts together:
Cost per litre = Σ (price ÷ bottle ml) × dose ml per litre and cost per US gallon = cost per litre × 3.785
Example: Part A at 18 per 1,000 ml and 2 ml/L costs 0.036 per litre, Part B at 16 per 1,000 ml and 2 ml/L costs 0.032, and Part C at 12 per 500 ml and 1 ml/L costs 0.024. The total is 0.092 per litre, which is 0.092 × 3.785 = 0.348 per gallon, or 1.84 for a 20 litre fill.
Enter the price in any currency and read the result in the same one. Add this to the grow light electricity cost to see your running costs, and use the hydroponic nutrient calculator for the ml per reservoir.
Costs are estimates and ignore water, pH products and wasted solution unless you add them as a part.
Frequently asked questions
Is a more expensive nutrient always more costly to use?
No. What matters is the cost per gallon of mixed solution, which depends on both the bottle price and how much you need per gallon. A pricey concentrate with a low dose can cost less than a cheap one with a high dose.
Which dose should I enter?
The amount from your feeding chart for the stage you are growing at. Doses usually go up as plants grow, so run the calculator again for the strongest stage to see your highest cost.
Does it include pH products and additives?
Only if you enter them as parts. Use one of the three part rows for a pH adjuster or supplement, with its price, bottle size and dose.
Why does the result show both per litre and per gallon?
Nutrient labels use either unit. Both are shown so you can compare products priced and dosed in different units.