Reach: how many people it helps
How many people this feature touches in a set period, usually per month. Use real numbers where you can: monthly active users hitting the affected screen, signups going through the flow, or customers who filed the request. Reach is what stops loud requests from a handful of users outranking quiet needs of thousands.
Impact: how much it helps them
How much the feature moves the needle for each person it reaches. The standard scale is 0.25 (minimal), 0.5 (low), 1 (medium), 2 (high), and 3 (massive). The coarse scale is deliberate: you cannot estimate per-user impact precisely, so do not pretend to.
Confidence: how sure you are
How sure you are about your Reach and Impact estimates. 100% means you have data, 80% means a solid hypothesis, 50% means a guess. Multiplying by Confidence discounts speculative bets so they do not outrank features backed by evidence.
Effort: how long it takes
Total work in person-weeks across design, engineering, and testing. Effort is the divisor: doubling the work halves the score. Estimate in whole or quarter weeks; precision beyond that is false precision.
A worked example
Say you are choosing between an onboarding checklist and a mobile app. The checklist reaches 1,500 signups per month, with high impact (2) on each, an 80% confidence backed by funnel data, and about 3 person-weeks of work:
(1,500 × 2 × 0.8) / 3 = 800
The mobile app reaches 1,200 users with high impact (2), but it is a bet: 50% confidence and roughly 12 person-weeks:
(1,200 × 2 × 0.5) / 12 = 100
The checklist scores eight times higher. Both features sounded equally exciting in the planning meeting: RICE makes the trade-off explicit instead of a gut call.
RICE vs a simple impact/effort score
A simple impact/effort score is two ratings per feature and works well for fast backlog triage. RICE earns its extra inputs when audience sizes differ: without Reach, a fix for 50 power users and a fix for 5,000 casual users can look identical. If your features all serve roughly the same audience, skip the overhead and use the feature priority calculator with its impact/effort matrix instead. Both tools share the same saved list, so you can switch frameworks without re-entering anything.
When RICE beats gut feel: stakeholders disagree about how many users a feature affects, a pet project keeps floating to the top of the roadmap, or you have analytics that nobody is using in planning. Writing down how many people a feature helps, and how sure you are about it, turns those arguments into checkable numbers.