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Financial function

ISPMT

Returns the interest paid during a specific period of an investment with equal principal payments.

Rarely usedDifficulty 1400 · AdvancedUsage rank #351 of 520
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When to use it

Interest for a period of a loan repaid in equal principal instalments (not equal payments). Also used by Lotus for compatibility.

The shape of it

Syntax
=ISPMT(rate, per, nper, pv)

Worked examples

  • First month

    =ISPMT(0.1/12,1,36,8000000) -64,814.81

    First month of an 8,000,000 loan at 10% over 36 months.

  • Period zero

    =ISPMT(0.1/12,0,36,8000000) -66,666.67

    Period 0: interest on the full balance.

  • Annual

    =ISPMT(0.1,1,3,8000000) -533,333.33

    Annual periods.

Worth knowing

  • Periods are 0-based here, unlike IPMT.
  • Interest = -pv × rate × (1 - per/nper).
  • Use IPMT for standard equal-payment loans.

Where it goes wrong

  • The 0-based period convention trips people up.
  • Not the same as IPMT for the same inputs.

Related

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