Plan greenhouse and garden loads with clear numbers. See device totals and monthly bills instantly. Make smarter upgrades, cut waste, and protect plants daily.
| Device | W | Hours/day | Days/week | Duty % | Qty | Estimated kWh/week |
|---|---|---|---|---|---|---|
| Grow Lights | 300 | 14 | 7 | 100 | 1 | 29.40 |
| Irrigation Pump | 750 | 1 | 4 | 60 | 1 | 2.57 |
| Ventilation Fan | 80 | 12 | 7 | 80 | 2 | 10.75 |
For each device, energy is estimated from active power, runtime, and duty cycle.
Garden electricity often rises because equipment runs on schedules, not on demand. This calculator converts device wattage, runtime, duty cycle, and standby draw into daily, weekly, and seasonal kWh. You can budget for propagation, winter protection, or extended photoperiods and avoid surprises when multiple circuits share the same supply.
For safety and capacity checks, compare the total watts to breaker limits and extension cord ratings. In greenhouses, spread heavy loads across circuits and stagger start times for pumps or heaters. Accurate inputs come from labels, plug meters, or manufacturer manuals, especially when using LED drivers and variable-speed fans.
Hours per day sets the active window, while days per week reflects irrigation days or weekend use. Duty cycle adjusts for thermostats, humidifiers, and heaters that cycle on and off. Standby watts capture controllers and smart plugs that draw power even when the main device is idle, especially with Wi‑Fi devices and timers.
Total cost is calculated by multiplying kWh by your rate per kWh, then scaling to month and season. If you enable emissions, the calculator multiplies kWh by your chosen factor to estimate kilograms of CO2. This supports reporting and helps prioritize changes with the largest impact, such as swapping lamps, adding insulation, or improving airflow.
The results highlight the top energy drivers by kWh per week. In many gardens, lighting dominates, but heaters and dehumidifiers can surpass lights during cool or humid periods. By seeing each device’s share, you can test alternatives like efficient fans, heat mats only under trays, or staged lighting zones for seedlings.
Use the device breakdown to run what‑if scenarios: reduce hours, lower duty cycle with better thermostats, or replace older pumps. Export CSV for recordkeeping and PDF for proposals. Over a season, small changes compound, improving plant stability while lowering operating costs. Recheck after maintenance, filter changes, or schedule updates to keep estimates accurate.
Use the nameplate on the device, the manual, or the manufacturer listing. For higher accuracy, measure with a plug-in power meter while the device runs normally and record the average watts.
Duty cycle is the percentage of time a device actively draws its rated power during the listed hours. Thermostats, humidifiers, and heaters often cycle. Enter 50% if it runs about half the time.
Controllers, smart plugs, Wi‑Fi timers, and chargers can draw power all day. Standby watts capture that hidden usage during the non‑running hours, improving monthly and seasonal estimates.
Start with your planned photoperiod, such as 14–18 hours for seedlings and 12 hours for many ornamentals. If lights are dimmed or staged, use separate rows per zone with different wattage and hours.
Enter your average energy rate as a blended rate: total bill minus fixed fees, divided by total kWh. For time‑of‑use or tiered pricing, run separate scenarios with different rates to bracket costs.
Yes. Change the season months, adjust hours or duty cycle, and toggle devices on or off. Export each run to CSV or PDF and compare totals to guide upgrades and scheduling decisions.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.