Tools / Planning

Cannabis grow cost calculator

The full cost of a cannabis cycle is the sum of seven inputs that hobby growers commonly track — seed cost, light electricity, soil or medium, nutrients, and the cycle length that multiplies the electricity portion. The calculator below collects each of those inputs, computes the full cycle cost, and divides by the expected yield to produce the per-gram figure that documented grow-report aggregations describe as the meaningful planning metric. The math is run live as the sliders move, so the trade-offs between fixture size, photoperiod, electricity rate, and yield expectation are visible immediately. Use the output as a planning figure alongside the strain's documented yield data and the tent's measured electricity draw rather than as a forecast for any specific cycle.

How the calculation works

Total kilowatt-hour consumption is the documented product of fixture wattage, hours per day, and days in cycle, scaled from watts to kilowatts. The formula is kWh = (watts ÷ 1000) × hours/day × (weeks × 7). Multiplying by the configured kWh price returns the electricity cost over the full cycle. Consumables — seed cost, nutrient cost, and medium cost — are summed as a one-cycle figure rather than amortized, because seed and medium are typically replaced each cycle at hobby scale. The grand total is the sum of electricity and consumables, and the per-gram figure divides the grand total by the expected yield in grams.

The calculator does not currently amortize larger hardware purchases — fixture, fan, filter, tent — across a multi-cycle lifetime, because hardware costs vary dramatically with brand selection and the documented service life of LED fixtures sits at five to ten years of nightly use, making any single amortization figure a wide approximation. Hobby budget worksheets typically add a 10-15% buffer on top of the consumables figure to cover small purchases not itemized here.

Reference ranges

Hobby growers commonly report total cost-per-gram between $0.50 and $3 depending on scale and electricity rate. The lower end of that band is documented as belonging to growers running large canopies under cheap electricity with reusable medium and high-yielding genetics. The upper end is documented as typical of small first-cycle tents under expensive metro electricity rates with modest yields. Commercial facilities are documented as targeting under $0.40 per gram at scale.

Electricity is documented as the single largest variable cost in most hobby tents — at typical home rates a 400 W fixture running an 18-hour vegetative schedule consumes roughly seven kilowatt-hours per day, which compounds quickly across a twelve-week cycle. The kWh price slider reflects published residential electricity rates that vary from roughly $0.10 per kWh in low-cost regions to over $0.35 per kWh in metro areas with high demand charges.

Related references: Lighting · Nutrients · Tent setup

Other tools: Light cost · Yield estimator · PPFD to DLI