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IRR Approximation from NPV at Two Discount Rates Calculator

Linear interpolation IRR estimate from two trial rates.

Approximates IRR using linear interpolation: IRR ≈ r₁ + NPV₁ / (NPV₁ − NPV₂) × (r₂ − r₁), given NPV at two discount rates r₁ and r₂.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

IRR ≈ r₁ + NPV₁/(NPV₁−NPV₂)·(r₂−r₁)

In depth

Approximates IRR using linear interpolation: IRR ≈ r₁ + NPV₁ / (NPV₁ − NPV₂) × (r₂ − r₁), given NPV at two discount rates r₁ and r₂.