Rough calculation of budget, schedule, or specs without exact measurement — standard in prep. Gets refined once reality hits.
You're in pre-production, the location hasn't been scouted yet, the crew size isn't fixed, and production management is asking for your equipment budget for five shooting days in an unknown studio. You make a guesstimate – because you have to calculate, even though half the parameters are missing. This isn't inaccuracy; it's craftsmanship. A guesstimate is the controlled speculation that gets production rolling in the first place.
In practice, it works like this: You take comparable projects from your experience, add a safety buffer (usually 15–25%), and provide a number that you can correct later. For shooting days, you estimate lighting setup time not based on data sheets, but on: How long did similar scenes take me? For technical specifications – resolution, frame rate, color depth – you also estimate: What is the minimum standard for this material, what can the budget afford? A guesstimate is therefore not a shot in the dark, but an experience-based prediction under uncertainty. The difference to precise calculations lies in time and information: guesstimates are made with 40% of the available information, final calculations with 90%. Both are legitimate, as long as it's clear which phase is currently underway.
On set, it happens constantly: the director changes a scene, and you have to quickly estimate whether your lighting setup still works or if you need to rebuild. Here, the guesstimate becomes a live decision-making aid – you don't need a measurement; you need speed. In post-production, you estimate similarly: How long will the color grading workflow take without having reviewed all the takes? The producer needs a number for the editing deadline.
The most important thing: document your guesstimate with the assumptions behind it. Don't just write "Budget: €50,000," but "€50,000 for lighting + grip for 4 shooting days, 8-person crew, studio interior, based on Project X (2023)." This makes your guesstimate transparent and traceable later when it needs to be corrected. This distinguishes professional estimation from pure guessing.