The annuity formula
Monthly deposits compounding monthly: FV = PMT × [((1+r)n − 1) / r]. The result surprises most people — over 20–30 years, growth usually exceeds contributions.
Start early beats save more
Ten extra years at the start outweighs doubling the monthly amount later, because compounding needs time. The cheapest money you will ever invest is the money you invest today.
Keep expectations honest
Markets do not move in straight lines — a 7% average includes crashes and booms. Treat the number as a planning guide, not a promise.
Frequently Asked Questions
How much should I save each month?
A common target is 20% of take-home pay (see the Budget Calculator). Any consistent amount beats a large irregular one.
What return should I assume?
Long-run stock market averages are often quoted near 7% after inflation — but use a conservative figure for planning, and never as a guarantee.
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