Tattoo Price Estimator

Estimated Cost takes whichever is larger of Shop Minimum and Estimated Hours times Artist Hourly Rate, using Math.max (line 19). For the calculator's default 20-square-inch design at $150/hour, the hours-times-rate figure comes out to $450, comfortably above an $80 shop minimum, so Shop Minimum never wins that comparison -- but for a very small design where hours-times-rate would fall below it, Shop Minimum becomes the number that actually sets your price.

At the default inputs, yes -- a 10% increase in either Design Size or Artist Hourly Rate raises Estimated Cost by roughly the same percentage, because Estimated Cost is built as Estimated Hours, which scales directly with Design Size, multiplied by Artist Hourly Rate (line 19), so the two inputs trade off symmetrically as long as Shop Minimum is not the binding floor.

Estimated Hours is computed from Design Size, Complexity, and Color Work alone (line 18) -- Artist Hourly Rate and Shop Minimum are never part of that formula. Artist Hourly Rate only enters one step later, when Estimated Hours is multiplied by the rate to produce Estimated Cost (line 19), so it can change your price without ever changing the hours the calculator reports.

Sessions Needed divides Estimated Hours by a fixed 5-hour maximum per session and rounds up with Math.ceil, with a floor of 1 session (line 27). Because Estimated Hours itself compounds Design Size with the Complexity and Color Work multipliers, a large photorealistic full-color piece can require dozens of hours and, therefore, dozens of sessions, while the same square footage in simple black-and-gray linework might still fit in a single sitting.