All hydroponic calculators
Free calculators for home hydroponic growers. Each one shows its formula and a worked example, so you can check the maths. They are grouped by what you are trying to do.
Nutrients and PPM
EC to PPM ConverterConvert EC and PPM on the 500, 640 and 700 scales.Hydroponic PPM CalculatorHow much water or nutrient to add to reach a target PPM.Hydroponic Nutrient CalculatorNutrient dose per part for your reservoir size.pH Adjustment Dosing CalculatorScale a test dose of pH Up or Down to your reservoir.DWC Nutrient Dosing CalculatorWeek-by-week feeding plan with water change weeks.MasterBlend 4-18-38 CalculatorGrams of MasterBlend, calcium nitrate and Epsom salt.Nutrient Cost per Gallon CalculatorWhat your nutrients cost per gallon, litre and fill.
Reservoir and water
Reservoir Volume CalculatorLitres and gallons for rectangular and round tanks.Reservoir Top-Off CalculatorWater to add and the ppm after topping off.Water Change Schedule CalculatorRefill dates, water and nutrient used over a grow.
Light and climate
Grow Light Electricity Cost CalculatorCost per day, month, cycle and year from watts and hours.VPD CalculatorVapour pressure deficit from temperature and humidity.DLI CalculatorDaily light integral from PPFD and light hours.
Estimates only: always follow your nutrient manufacturer's label and check your readings with a calibrated meter.