Rule of 72
A quick way to estimate how long it takes an investment to double at a given growth rate.
"Math for people who need the answer before the meeting ends."
What is Rule of 72? A quick way to estimate how long it takes an investment to double at a given growth rate. The rule of 72 makes compound growth intuitive.
At 7% growth, money doubles in about 10 years.
The rule of 72 makes compound growth intuitive.
Use it to sanity-check growth and interest projections.
Use the model. Pick the move.
A quick way to estimate how long it takes an investment to double at a given growth rate. You've just seen this: At 7% growth, money doubles in about 10 years. Which lever does the model recommend?
Pick a lever. There are no neutral ones — every incentive funds a behavior somewhere.
Pick a reaction to Rule of 72
One tap. We'll point you at the most useful next surface based on how this hits.
The full taxonomy entry
Every concept in the Atlas uses the same structure — so Rule of 72 can be compared, recombined, and cited like an element on a periodic table.
- Business
- Leadership
- Government
- Healthcare
- Education
- Sales
- Marketing
- AI
- Negotiation
- Media
- Public Policy
- Relationships
- Where in our org would Rule of 72 most often show up unnoticed?
- Which metric, ritual, or contract clause quietly rewards Rule of 72?
- If we removed every payoff for Rule of 72, what behavior would replace it?
- Who benefits when Rule of 72 persists — and who pays the cost?
- People defend the status quo using the language of rule of 72.
- Decisions cluster around the easiest narrative rather than the strongest evidence.
- New data changes the slide deck but not the decision.
- Anyone naming the pattern is treated as the problem.
Every Atlas entry is a node in a knowledge graph. See the related rail below to follow the connections.
See Rule of 72 through 2 lenses
Each layer of the Incentives OS reframes this concept with its own thinkers, vocabulary, and diagnostic question.
Do you actually know Rule of 72?
Three quick questions. Result is saved into your review streak — come back when the term is due to lock it in.
Which best describes Rule of 72?
Worked example, counter-example & concept map
On-demand AI analysis grounded in the Lab's research. Cached on your device after first run.
When you encounter Rule of 72, your prefrontal cortex has to do extra work to override the automatic response — and that override budget is finite.
Executive control, planning, impulse override, working memory, System 2. First thing to go offline under stress, fatigue, or low blood sugar. Why your 4pm decisions are worse than your 9am ones.
See Prefrontal in the Brain Atlas →Picked for you, from the Atlas
Ranked by shared learning paths, overlapping chips, and what you've saved.
Ignoring general statistics in favor of specific, vivid information.
Posterior = (likelihood × prior) / evidence.
Update beliefs in proportion to the strength of new evidence.
Start with a prior; update with new evidence.
Novices experiencing early success, often due to variance and small samples.
High-impact, hard-to-predict, retrospectively explainable events.
Send the card, not just the link
A pre-rendered social card with the title, eyebrow, and URL. Copy the link, post it anywhere, or download the SVG for slides.
More definitions to follow
Every term in the Atlas connects to a dozen others. Pick any of these and see where it takes you.
Adding external rewards reduces intrinsic motivation.
Responding in kind — favors for favors, harms for harms.
Small step → catastrophic outcome, without the intermediate causal links.
Daily one-line capture of the single most important thing you learned that day.
Someone who incites others to take illegal or rash action, often to expose or discredit them.
We accept vague, general statements as personally meaningful.
Anchor a peak resourceful state to an imagined spot on the floor; step into it on demand before high-stakes moments.
Influencing the beliefs and actions of a crowd through psychological techniques.
The capacity to recognize, understand, and manage emotions — your own and others'.
Cut-rate state reinsurance lets insurers expand coverage in storm-prone zones, socializing the risk.
We believe we understand others better than they understand us.
Neural mechanism of learning — connections strengthened by repeated activation.