The 10% Planning Rule
Never spend more than 10% of an execution period planning it.
- Difficulty
- Starter
- Time to result
- ~days to results
- Steps
- 3
- Confidence
- 85%
A hard-fought heuristic capping planning time at 10% of the period being planned: a week gets half a day, a month gets about three days. It prevents the creeping expansion of planning that steals execution time, on the logic that you rarely know what's ahead until you've launched or learned something.
Origin
A rule Lane Shackleton's team at Coda lives by, described as hard-fought because they made the over-planning mistake before. Lenny notes he independently arrived at the same heuristic.
Core principles
- 01Planning expands to fill available time if uncapped
- 02You don't truly know what's ahead until you launch or learn something
- 03Over-planning is a slow accumulation from repeatedly extending planning windows
- 04A fixed percentage cap keeps planning proportional to execution
How to run it
- 1
Fix the execution period
Decide the time period you're planning for — a week, a month, a quarter.
Pro tip Be explicit about the window before you start planning.
Watch out An undefined period invites unbounded planning.
- 2
Cap planning at 10% of it
Budget no more than 10% of that period for planning: ~half a day for a week, ~three days for a month.
Pro tip Write the cap down as a team rule so it's not renegotiated each cycle.
Watch out Resist the 'planning felt rushed, let's make it three weeks instead of one' pressure — that's the trap.
- 3
Launch and learn instead of over-planning
Once the cap is hit, move into execution; expect to learn the rest by launching rather than by planning further.
Pro tip Treat the remaining unknowns as things only execution can resolve.
Watch out Repeatedly extending planning windows compounds into far too much planning over time.
In the wild
Coda adopted the 10% cap after over-planning — teams kept saying planning felt rushed and stretched a one-week plan to three weeks, and the byproduct over time was planning way too much.
→ The fixed 10% cap keeps planning proportional and preserves execution time; Lenny independently found the same heuristic works.
Common mistakes
Extending planning because it 'felt rushed'
Stretching a planning window each time it feels tight compounds into chronic over-planning that steals execution time across many cycles.
Trying to plan away all uncertainty
You often can't know what's ahead until you launch or learn something, so extra planning yields diminishing returns versus just executing.
Is it for you?
Best for
Teams that lose execution time to bloated, ever-expanding planning cycles
Not ideal for
High-risk, hard-to-reverse initiatives where deeper upfront planning genuinely reduces catastrophic risk
From the transcript
“what we call 10% planning rule which is essentially you know just ensure that you're not for a given time period planning for more than…”
From the episode
What sets great teams apart
Lane Shackleton (CPO of Coda)