Proposal Bisnis Produksi Helm Motor Garuda

= 69.230.769 + 59.171.598 + 54.619.936 + 63.023.003 + 59.252.396 −500.000.000

= 301.527.095 −500.000.000

NPV 2= 301.527.096

Langkah 2: Menginterpolasi untuk Mendekati IRR

IRR berada di antara 20% dan 30%.

IRR ≈ r1+(NPV1/NPV1−NPV2) × (r2−r1)

Di mana:

r1=20%
r2=30%
NPV1=110.855.995
NPV2=301.527.096
Menghitung IRR:

IRR ≈ 20% + (110.855.995/110.855.995−301.527.096) × (30%−20%)

IRR ≈ 20%+ (110.855.995/190.671.141) × 10%

IRR ≈ 20%+0.58 ×10%