back-of-envelope
Hastily scrawled calculation
Back-of-envelope describes rough, informal calculations or estimates made quickly without careful analysis—the kind you might sketch on whatever paper is handy: a back-of-envelope calculation suggests we'd need about fifty thousand.
The phrase implies approximate rather than precise figures, adequate for preliminary thinking but not final decisions.
Informed guess at quantity
- approximationNear but inexact value
- roughUneven in surface
- ballparkSports venue or estimate
- guesstimateRough, intuitive calculation
napkin math · order of magnitude · sketch · preliminary · informal · imprecise · hasty · first pass
Mealtime wiping cloth
- scrap paperDiscarded pages repurposed for notes
- dinerCasual American eatery
- meetingGathering for discussion
- impromptuWithout advance preparation
offhand · casual · spontaneous · jotted · scribbled · sketched · handwritten · informal
Capacity to succeed
- sanity checkVerification of basic soundness
- reality checkConfrontation with actual circumstances
- plausibilitySeeming likely true
- ballparkSports venue or estimate
threshold · benchmark · proof of concept · order of magnitude · gut check · scoping · directional · indicative
estimate
Informed guess at quantity
- approximationNear but inexact value
- roughUneven in surface
- ballparkSports venue or estimate
guesstimate · napkin math · order of magnitude · sketch · preliminary · informal · imprecise · hasty · first pass · sanity check
napkin
Mealtime wiping cloth
- scrap paperDiscarded pages repurposed for notes
- dinerCasual American eatery
- meetingGathering for discussion
impromptu · offhand · casual · spontaneous · jotted · scribbled · sketched · handwritten · informal · makeshift
viability
Capacity to succeed
- sanity checkVerification of basic soundness
- reality checkConfrontation with actual circumstances
- plausibilitySeeming likely true
ballpark · threshold · benchmark · proof of concept · order of magnitude · gut check · scoping · directional · indicative · exploratory
- Estimation Typesguesstimation, order of magnitude, ballpark figures, margin of error, confidence interval
- mental mathmental math, mental arithmetic, estimation, guesstimate, ballpark
- heuristicsrule of thumb, heuristic, guideline, mental shortcut, educated guess
- guessesguess, conjecture, supposition, speculation, surmise
- Imprecisevague, fuzzy, rough, hazy, murky
back-of-envelopepeer-reviewed
Evaluated by field experts
rigorous · exact · meticulous · data-driven · evidence-based
back-of-envelopeformal
Following strict protocol
certified · audited · published · documented · by-the-book
back, envelope, backs, backed, backing, backside, backward, backwards, envelop