Hydroponic Calculators
Four free tools built for apartment growers. No signup, no email, no nonsense. Pick the one you need and get exact numbers for your setup in under 60 seconds.
Beginner Shopping List Builder
Tell us your goal, experience level, and budget. Get a complete prioritised shopping list with every item explained, what to buy first, and direct Amazon links. Real prices, no guesswork.
Build my list →Grow Light Calculator
Enter your grow space size and crop type. Get the exact PPFD target, true wattage needed, daily light hours, hang height, and DLI. Works for LED panels, bars, and all-in-one kits.
Calculate my light →pH and Nutrient Calculator
Pick your crop and system type, enter your reservoir size. Get exact pH range, EC target, PPM, water temperature, and nutrient doses in millilitres. Covers 15 hydroponic crops.
Get my recipe →Seed to Harvest Countdown
Enter your crop and planting date. See your current growth stage, estimated harvest date, days remaining, and the exact signs to look for when it is ready to pick. Real-time tracking.
Start my countdown →All tools are free forever with no signup required. Built by Urban Hydro Space for apartment growers who want real answers, not vague advice. Every number is backed by research and verified math.
❓ Common questions
🌱 I am a complete beginner. Which tool should I use first?
Start with the Shopping List Builder. It asks 3 questions and gives you a complete list of everything you need to buy, in order, with links and prices. Once you have your equipment, use the pH and Nutrient Calculator for your first grow and the Seed to Harvest Countdown to track your progress.
💰 Are these tools really free?
Yes, completely free with no signup, no email gate, and no limits. The tools contain Amazon affiliate links. If you buy a product through one of those links, we earn a small commission at no extra cost to you. That is how we keep the tools free.
📊 How accurate are the calculations?
Every number is calculated from verified source data, not hardcoded guesses. PPM values are computed from EC using the standard 700 scale formula. DLI is computed from PPFD and light hours. Wattage is derived from your grow area and crop-specific watts per square foot. Shopping list budgets are calculated from exact Amazon prices as of March 2026.
🍅 What crops do the tools support?
The pH Calculator and Seed to Harvest Countdown cover 15 crops: lettuce, spinach, arugula, basil, mint, cilantro, chives, tomatoes, peppers, cucumbers, strawberries, microgreens, bok choy, wheatgrass, and edible flowers. The Grow Light Calculator covers 4 categories (seedlings, leafy greens and herbs, fruiting vegetables, and strawberries). The Shopping List Builder covers herbs, fruiting, microgreens, and mixed setups.
📱 Do the tools work on mobile?
Yes. All four tools are fully responsive and work on phones, tablets, and desktop browsers. The interactive buttons, input fields, and results all adapt to your screen size automatically.