Money, Explained From the Inside

Tools / Plan ahead / Chapters 1 and 6

Margin & net worth

Two numbers describe any financial life: the monthly margin (a flow) and net worth (a stock). Income alone says neither.

1 · The idea

Margin and net worth

Margin is what is left of a month after the commitments you cannot easily change and the spending you can. Net worth is a snapshot: everything you own at today’s value minus everything you owe.

The formula

Margin = take-home − committed − everyday Net worth = assets − liabilities

Committed
rent or mortgage, loan payments, insurance, contracts
Everyday
food, transport, leisure, anything flexible
Assets
cash, investments, pensions, property, vehicles at realistic value

2 · A worked example

Take-home $4,000, committed $2,300, everyday $1,300: margin $400.00 (10%). Assets $25,000 minus debts $14,500: net worth $10,500.

3 · Now use your own numbers

Change anything. The result updates instantly.

Rent or mortgage, loan payments, insurance, subscriptions you are tied into.

What you own
What you owe
Monthly margin
$400.0010% of take-home pay
Net worth
$10,500Assets $25,000 − liabilities $14,500
Committed share
57%The part of your pay that is spoken for before the month begins.
Everyday share
33%

What this means

A good income with a thin margin is still fragile. A modest income with a steady margin compounds into wealth. Margin is what turns income into net worth.

A negative net worth is common early on, especially with student or car debt. The direction of travel matters more than the starting point.

Illustrative, not personal advice. Inspired by Chapters 1 and 6 of Money, Explained From the Inside. Your figures stay in this browser. Real products add terms, taxes and conditions that this simple model leaves out.

4 · Take care

What this tool can’t see

  • Use realistic market values for property and vehicles, not what you paid.
  • Count irregular costs (insurance, holidays, repairs) as monthly averages, or margin looks better than it is.

5 · Go further

Where this fits

See it in a life:

DavidIncome without wealth MariaThe quiet power of margin

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