Learning curve

Learning curve describes how average labour time per unit falls by a fixed percentage each time cumulative production doubles. An 80% curve means average time per unit falls to 80% of its previous level whenever output doubles.

ByHoang TruongUpdated June 30, 2026

FrameworkLearning curve

See it move

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The first unit of a specialist component takes 100 hours to assemble. Under an 80% learning curve, each doubling of cumulative output cuts the average time to 80% of its previous level: 80 hours at 2 units, 64 hours at 4 units, and 51.2 hours by 8 units. Total time keeps rising, but at an ever-slowing rate, which matters for quoting long production runs.

Where it fits

SubjectCost AccountingAdvancedTopicCost Behaviour & EstimationAdvanced

The formula

LaTeX

\bar{Y}_n = Y_1 \cdot n^{b}, \quad b = \frac{\log r}{\log 2}

Variables

$\overset{ˉ}{Y}_{n}$: Cumulative average time per unit after producing n units in total (hours per unit)
$Y_{1}$: Time required to produce the very first unit (hours)
$n$: Cumulative number of units produced
$b$: Learning exponent — a negative number derived from the learning rate; equals log(r) ÷ log(2)
$r$: Learning rate expressed as a decimal (e.g. 0.80 for an 80% learning curve)

Each time cumulative output doubles, the average time per unit falls to r × its previous level; b is negative so Ȳ_n falls as n rises