Drip Irrigation Calculator
AgricultureCalculate daily water requirement, number of drippers, total flow rate, and irrigation duration for your field. Enter crop type, area or plant count, and spacing — get a complete drip system design estimate instantly. Supports acres, hectares, and bigha with 18 crops.
Field Details
Results
* ET values based on FAO-56 Penman-Monteith guidelines with crop coefficients. Actual requirement varies with local climate, soil, and growth stage.
Crop Water Requirement Reference (India)
| Crop | ET (mm/day) | Typical Spacing | Drippers/Plant |
|---|---|---|---|
| Tomato | 4.5–6.0 | 1.5m × 0.6m | 2 |
| Chilli | 3.5–5.0 | 1.5m × 0.45m | 2 |
| Onion | 3.0–4.5 | 0.3m × 0.15m | 1–2 (inline) |
| Sugarcane | 5.0–8.0 | 0.9m row | Inline drip |
| Banana | 6.0–8.0 | 1.8m × 1.5m | 3–4 |
| Grapes | 3.5–5.5 | 3m × 1.5m | 2–4 |
| Cotton | 4.5–6.5 | 0.9m × 0.6m | 2 |
| Mango / Citrus | 5.0–7.0 | 6m × 6m | 4–8 |
| Pomegranate | 4.0–6.0 | 5m × 3m | 4 |
| Cucumber | 4.0–6.0 | 1.5m × 0.6m | 1–2 |
Dripper Flow Rate Selection Guide
| Flow Rate | Best For | Soil Type |
|---|---|---|
| 1–2 LPH | Closely spaced crops (onion, garlic), sandy soils | Sandy / Light |
| 4 LPH | Most vegetables (tomato, chilli, cucumber), most common in India | Loamy / Medium |
| 8 LPH | Orchards (mango, citrus), widely spaced crops | Clay / Heavy |
| 12–16 LPH | Large trees, deep-rooted plants, high-demand crops | Clay / Sandy loam |
Frequently Asked Questions
How do I calculate the water requirement for drip irrigation?
Water Requirement (L/day) = Area (m²) × Crop ET (mm/day) ÷ Irrigation Efficiency. Crop ET = ETo (reference ET) × Kc (crop coefficient). For example, tomato in summer: ET ≈ 5 mm/day, 1 acre (4047 m²) field, 90% efficiency → 4047 × 5 ÷ 0.90 = 22,483 L/day (22.5 m³/day). Our calculator uses FAO-56 Kc values and seasonal adjustments for accurate results.
How many drippers do I need per acre?
It depends on plant spacing. For tomato (row 1.5m × plant 0.6m): Plants per acre = 4047 ÷ (1.5 × 0.6) = 4,497 plants. At 2 drippers/plant = 8,994 drippers/acre. For wider-spaced crops like mango (5m × 5m): 4047 ÷ 25 = 162 plants × 2 drippers = 324 drippers/acre. Use our calculator — enter your crop, spacing, and area to get the exact count.
What is the ideal dripper flow rate for vegetables?
For vegetables (tomato, chilli, onion) with 0.6–1.0m plant spacing: use 2–4 LPH drippers. For fruit orchards (mango, citrus) with 4–6m spacing and deep-rooted plants: use 4–8 LPH drippers. For sandy soils, use lower flow rates and longer durations to prevent runoff. For clay soils, use lower flow rates to prevent waterlogging. 4 LPH is the most commonly used dripper in India.
How long should I run drip irrigation per day?
Irrigation Duration = Daily Water Requirement (L) ÷ Total Flow Rate (LPH). Example: 10,000 L/day needed, 5000 LPH total flow → 2 hours irrigation. In summer, vegetables may need 1.5–3 hours/day. In winter, 0.5–1.5 hours/day. In monsoon season, skip irrigation when rainfall exceeds crop ET. Split into 2 sessions (morning + evening) for better uptake.
How much water does drip irrigation save compared to flood irrigation?
Flood irrigation efficiency is 40–50%. Drip irrigation efficiency is 85–95%. Water savings = 40–50% compared to flood/furrow irrigation. For 1 acre of tomato in summer: flood may use 50,000 L/day vs drip using ~22,500 L/day — saving 27,500 L (55%) daily. Over a 120-day crop season: 3,300,000 L (3,300 m³) of water saved per acre.
What is the drip irrigation calculation formula?
Key formulas: (1) Plants/acre = 43,560 ÷ (row spacing ft × plant spacing ft). (2) Drippers = Plants × drippers per plant. (3) Water req. (L/day) = Area (m²) × ET (mm/day) ÷ efficiency. (4) Irrigation time (hrs) = Water req. (L) ÷ Total flow (LPH). (5) Lateral length (m) = Area (m²) ÷ row spacing (m). (6) Water saved = [(Flood water - Drip water) ÷ Flood water] × 100%.
What is a good drip irrigation schedule for tomatoes in India?
Tomato (1.5m × 0.6m spacing, 1 acre): ~4,500 plants, 2 drippers/plant at 4 LPH = 36,000 LPH total flow. Summer water need: ~22,500 L/day. Irrigation time: 22,500 ÷ 36,000 = 0.625 hrs = 37 minutes/day. Run 6:00–6:37 AM. Winter: ~15,000 L/day → 25 minutes/day. Fertilizer (fertigation) can be applied through the drip system during irrigation.