How is payback period calculated here?

Investment divided by net annual savings, where net is annual savings minus annual support. At the defaults, $185,000 over $53,500 is 3.46 years.

Why is payback blank when savings do not clear support?

No net cash arrives, so the investment never repays. The page states the blank and still shows the negative five-year net value.

What does the five-year return add to payback?

It shows the net value after five years as a share of the investment. Two projects can share a payback but differ sharply over five years.

Should I discount the cash flows?

This page does not. For long-lived programs, discount the annual net savings at your cost of capital before comparing options, because payback ignores the time value of money.

Composites, Fiberglass & Advanced Materials calculator

Lightweighting Payback Calculator

Work out how long a lightweighting investment takes to pay back and what it returns over five years. The target payback you enter turns the result into a pass or a warning.

What this calculator does

Payback, net annual savings and five-year value for a lightweighting investment, judged against your target.

Formula used

Net annual savings = annual savings − annual support cost
Payback period = investment ÷ net annual savings, blank when net savings are not above zero
Five-year net value = net annual savings × 5 − investment
Five-year return = five-year net value ÷ investment × 100, blank when investment is zero

Inputs explained

Lightweighting Investment: Design, tooling, qualification and launch cost of the change.
Annual Savings: Yearly saving from less weight, fuel or material use.
Annual Support Cost: Yearly support, inspection and program cost of the change.
Target Payback: Payback the business case must beat, from capital rules.

How to use the result

Best suited to screening a metal to composite change, comparing two lightweighting options, setting a payback hurdle for a program.
Payback ignores cash flow after break-even and the time value of money. A savings case built on fuel prices or duty cycles is only as good as those estimates.

Current U.S. benchmarks

The producer price index for plastic resins and materials stands at 280.569 (BLS, Aug 2026), up 6.6% from a year earlier. Quotes priced off last quarter's material cost miss this move.
Steel mill PPI stands at 381.162 (BLS, Aug 2026), up 23.4% from a year earlier. New factory orders are up 8.5% year over year (Census).

Common questions

How is payback period calculated here? Investment divided by net annual savings, where net is annual savings minus annual support. At the defaults, $185,000 over $53,500 is 3.46 years.
Why is payback blank when savings do not clear support? No net cash arrives, so the investment never repays. The page states the blank and still shows the negative five-year net value.
What does the five-year return add to payback? It shows the net value after five years as a share of the investment. Two projects can share a payback but differ sharply over five years.
Should I discount the cash flows? This page does not. For long-lived programs, discount the annual net savings at your cost of capital before comparing options, because payback ignores the time value of money.

Last reviewed 2026-10-01.