Costing & FinanceFree calculatorPDF, Excel, Word export

Supplier Learning Curve Price Reduction Calculator

Suppliers get faster and cheaper as they repeat a job. Wright's learning curve puts a number on that, so a request for a price reduction at the second or third production lot is backed by an equation and not just pressure.

Your numbers

Cost of the first unit

Supplier's cost, or price, of the first production unit.

Learning rate

Each doubling of cumulative output cuts unit cost to this percent of the previous level.

Cumulative units produced

100 units

Your results

Cost of the Nth unit

$163

Reduction from the first unit

66%

Learning exponent

-0.2345

Negative number; unit cost = first unit cost x units^b.

Cumulative cost of all N units

$21,011

Continuous approximation of the sum of unit costs.

Average cost per unit over N units

$210

Learning curves describe labor and process learning, not material cost. Apply the curve to the learning-sensitive portion of the price, and confirm the rate with the supplier's actual history.

Save results:

Nth unit cost and cumulative average vs units produced

Sweeps Cumulative units produced from 1 to 400, holding your other inputs fixed.

Price trend analysis from ERP receipts

Optional: we can chart price versus cumulative volume per part from your purchase history.

Optional. The tool and every export work without this. No spam.

How to use it

Enter the cost or price of the first unit, pick a learning rate and set the cumulative number of units. The tool returns the expected cost of the Nth unit, the percentage reduction from the first unit, and the average cost across all units made so far. Use the chart to see where the curve flattens, because most of the gain comes in the first few doublings. Then compare the supplier's quoted price at your lot size with the curve to see if the price-down is realistic.

The formula

Wright's model says unit cost falls by a fixed percentage every time cumulative output doubles. The cost of unit n is T1 times n raised to b, where b is the natural log of the learning rate divided by the natural log of 2. A 90 percent curve gives b of about minus 0.152. The cumulative total here uses an integral approximation, which is accurate to a small error for lots beyond a handful of units and simple enough to check by hand.

Unit n cost = T1 x n^b
b = ln(rate) / ln(2)
90% curve: unit 2 costs 90% of unit 1, unit 4 costs 81%
Lower rate means steeper learning

Reading the result

A reduction of 25 to 35 percent by unit 100 is plausible for labor-heavy assembly at an 85 percent rate, while mostly automated work learns far less. Use the result as a target range, not a demand. If the supplier shows flat pricing across many lots, ask for a cost breakdown and test whether setup, programming and first article effort have really dropped out of the price.

Common mistakes

Applying the curve to the whole price, including raw material and purchased components, overstates the reduction. Split the price into learning-sensitive labor and overhead and flat material, then apply the curve only to the first group. Also avoid mixing cumulative output across different part numbers unless they share the same process. Pull cumulative quantity from purchase order receipts by part and supplier in your ERP.

Frequently Asked Questions

What is a typical learning rate?

Aerospace assembly is often cited around 80 to 85 percent, general machining and fabrication closer to 90 to 95, and highly automated work near 95 or higher. Verify against the supplier's own history before using it.

Wright or Crawford curve?

This tool uses Wright's cumulative model, where the cost of each unit falls with cumulative output. Crawford's model uses the same equation but applies it to unit cost and is the common reading. Both give the same unit cost formula here.

Does the curve apply to price or cost?

It describes cost. Price follows cost only if the supplier shares the gain, which is the point of negotiating. Use the curve to argue the cost trend and then ask what portion becomes a price reduction.

Why does the total use an approximation?

The exact total is a sum over each unit. The integral form is close for larger lots and lets the formula run in a browser tool without loops. Differences matter only for very small quantities.

If you want supplier price histories and cumulative volumes pulled from your ERP to test these curves automatically, Netray can build a read-only view.

Talk to an Expert Explore More Free Tools

Related Tools

Costing & Finance

More Costing & Finance tools

See all

Back to All Tools