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Overlap cost calculator

Short answer

Every overlapped strip is seed, fertiliser, spray and fuel paid for twice. Enter your own numbers below to see what overlap costs you per season, and what cutting it with guidance is worth. The defaults are deliberately modest; change any of them.

Updated · Oran Dynamics

Units

Wasted per season

Without guidance: —

With guidance: —

Overlap strip per pass: — → —

Saved per season

—

— less ground covered twice

Enter a number in every box to see the result.

Formula: saving per season = field area × passes × (overlap without − overlap with) × cost per unit area per pass. Payback = subscription price ÷ (cost per unit area × (overlap without − overlap with)).

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How to use it

  • Area: the ground you cover per pass, across all the fields you'd use guidance on.
  • Working width: the implement's width, or the bout width for a spreader.
  • Passes per season: how many times each acre is sprayed, spread or worked in a year.
  • Cost per acre per pass: the product applied plus the running cost of the pass (fuel, wear, your time). Product cost is usually most of it.
  • Overlap without and with guidance: the share of each pass that lands on ground already covered. Use your own estimate if you have one.

Where the default numbers come from

  • 10% overlap without guidance. Kansas State University found "the typical unaided driver has an overlap error of 10 percent of the toolbar width" (Price, MF3069, 2012). North Dakota State University Extension uses the same 10% estimate (SF1176-4, revised 2023).
  • 5% with guidance. We assume phone guidance only halves unaided overlap. No published study measures phone-app guidance on its own, so this is our deliberately cautious estimate. For comparison, Kansas State lists typical overlap settings of 12–15 in. per pass for WAAS-class guidance and 3–4 in. for RTK, and NDSU cites a study where guidance cut overlap from 10% to 0.5%.
  • Irregular fields overlap more. NDSU notes odd-shaped fields "may increase inputs by as much as 15 percent". If your fields are awkward, raise the "without" figure.
  • $25 per acre per pass is a placeholder for product plus running cost. Use your own.

Sources (read 20 October 2026): Kansas State University MF3069 · NDSU Extension SF1176-4

What the calculator leaves out

It counts only overlap. It ignores missed strips (which cost yield rather than inputs), time saved, driving at night, and operator fatigue, all of which tend to favour guidance. It also assumes the guidance is used on every pass. Phone GPS is accurate to a metre or two on newer dual-frequency iPhones, up to about 5 m on older ones, so on narrow implements the "with guidance" figure should be closer to the "without" one; see accuracy.

Questions

It's area × passes × the share of each pass overlapped × the cost per acre per pass. At 200 acres, 3 passes, a 5-point cut in overlap and $25 an acre per pass, that's $750 a season.

Kansas State University puts the typical unaided driver at 10% of the implement width, and NDSU uses the same 10% estimate; irregular fields can be higher.

At the defaults, the US$89 subscription is covered by the overlap saved on about 72 acres of a single pass. Your numbers will differ; put them in above.

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