Essential Oil Diffuser Calculator

Drop count is built from two multipliers, not from room volume directly. Your intensity choice sets a base rate per 100 mL of water — 3 drops at setting 1, 6 at setting 2, 10 at setting 3 — and room size applies a step factor of 1.0, 1.3 or 1.6 on top of it. That factor is the detail most people miss: it is a three-bracket staircase drawn at 200 and 500 square feet, so 201 and 500 square feet call for the identical 23 drops in a 300 mL tank, and 501 square feet jumps straight to 29. Nudging the room figure within a bracket changes nothing at all. Across their full ranges, intensity is the more powerful control, swinging a default 300 mL tank from 9 to 30 drops.

Everything else follows: oil volume is drops times 0.05 mL, cost assumes ten cents a drop, and sessions per bottle divides 300 drops — a 15 mL bottle at that same drop size — by your per-fill count, rounded down to whole fills. Run time is a separate calculation entirely, tank capacity divided by mist output, which is why it ignores intensity and room size completely and why a bigger tank raises run time while a faster mister lowers it in equal measure. The on and off cycle is intensity-driven and always totals 90 minutes: 60 on and 30 off at the lightest setting, inverting to 30 on and 60 off at the strongest, which is the standard guard against olfactory fatigue. Every input is floored — 10 square feet, 50 mL, 5 mL per hour — and intensity is rounded and clamped into the 1 to 3 range. Ceiling height, ventilation, oil viscosity and the very wide variation in dropper orifice size are not modelled.