How to Project Exponential Growth with GROWTH

GROWTH fits an exponential curve — for things that grow by a percentage each period — and projects it forward.

You will learn to

• Project the next period with GROWTH
• See how much a straight line underestimates compounding growth
• Extract the implied growth rate per period

How it works

GROWTH(known_ys, [known_xs], [new_xs]) fits an exponential curve, y = b × m^x, through your data and returns its values at new x’s. Use it when a quantity grows by a roughly constant percentage each period — users of a viral app, a bacterial culture, compound sales growth — rather than by a constant amount.

A straight-line TREND underestimates this kind of growth, and the gap widens every period. The ratio of two consecutive GROWTH values, minus 1, is the per-period growth rate the curve implies. GROWTH needs all y values to be positive.

=GROWTH(B2:B9,A2:A9,9)