Hydroponics calculators
Every calculator runs the same engine that powers the Hydroponicity app: real formulas with the assumptions stated, free and without signup. Pick the question you're trying to answer.
Nutrients & Water
EC ↔ ppm converter
Convert between EC and ppm on any meter scale (500 / 640 / 700), with 25 °C temperature correction.
Targets “ec to ppm hydroponics”
Fertilizer label decoder
Turn a guaranteed-analysis N-P-K label (oxide form) into the elemental percentages every ppm calc needs.
Targets “convert P2O5 to P”
Recipe solver
The real multi-salt engine: enter target ppm, get grams per fertilizer and a solved ion balance. One free solve.
Targets “hydroponic nutrient calculator”
Dilution & injector calculator
Solve C₁V₁ = C₂V₂ for any missing value, and size stock concentrate for a 1:R injector, with the ratio convention made explicit.
Targets “nutrient dilution calculator”
Environment & Climate
VPD calculator
Air temp, humidity, and leaf-temperature offset → air and leaf VPD in kPa, checked against stage targets.
Targets “vpd calculator”
Dehumidifier sizing
Pints-per-day capacity for a grow room (from water fed) or a drying room (from wet harvest weight).
Targets “grow room dehumidifier size”
Humidifier sizing
Moisture output needed to hold a target RH against air exchange, from room volume and current conditions.
Targets “grow room humidifier size”
AC / BTU sizing
Turn light and equipment wattage into the BTU/hr and tonnage of cooling the room actually needs.
Targets “grow room BTU calculator”
Exhaust fan & carbon filter CFM
Room volume and exchange rate → base CFM, derated for carbon filter and ducting so the fan you buy keeps up.
Targets “grow tent fan size calculator”
CO₂ enrichment calculator
Grams of CO₂ to reach a target ppm, ongoing loss to air exchange, and time-to-setpoint for your injector.
Targets “grow room co2 calculator”
Lighting
Irrigation & Systems
Energy & Economics
Electricity cost calculator
Add up lights, fans, and pumps by wattage and hours → daily, monthly, and per-cycle running cost.
Targets “grow light electricity cost”
Yield estimator & production planner
Growth rate, area, and cycle length → predicted yield, cycles per year, annual output, and revenue.
Targets “hydroponic yield calculator”