Most Post Office MIS spreadsheets stop at one multiplication: deposit times rate, divided by twelve. That gives you the monthly payout, and it is the easy part. The two questions people actually ask after opening the account are what happens if the monthly interest is put to work instead of spent, and how much it costs to break the account early. This sheet answers all three, with live formulas you can check.
Download: Post Office MIS calculator (.xlsx, free)What the sheet does
- Works out the monthly interest, the yearly total and the full five-year interest for any deposit.
- Checks your deposit against the limit for a single or a joint account.
- Shows what the monthly interest grows to if each payout goes into a Post Office RD, using the quarterly compounding formula the post office uses.
- Works out the deduction and the amount returned if you close the account early, month by month.
- A plain .xlsx with no macros. It opens in Excel, Google Sheets and LibreOffice, licensed CC BY 4.0.
The scheme rules the sheet uses
- Interest rate: 7.4% a year for October to December 2026, unchanged from the previous quarter. It is paid every month, and the rate you open at stays fixed for the full five years.
- Deposit: ₹1,000 minimum, in multiples of ₹1,000. Up to ₹9 lakh in a single account and ₹15 lakh in a joint account.
- Closing early: not allowed in the first year. Between one and three years, 2% of the deposit is deducted; between three and five years, 1%.
- Tax: the interest is added to your income and taxed at your slab. MIS gets no deduction under 80C.
Source: Small savings interest rates for Oct–Dec 2026 (Ministry of Finance, 30 Sep 2026), as reported
₹9 lakh in a single account, worked through
- Monthly interest: ₹5,550. In a year: ₹66,600. Over five years: ₹3,33,000, and the ₹9 lakh comes back at maturity.
- Put each ₹5,550 into a Post Office RD at 6.7% instead, and after 60 instalments the RD is worth about ₹3,96,080.
- That is about ₹63,080 more than spending the interest, without adding a rupee of your own.
The MIS-plus-RD pairing is the classic post office ladder for people who do not need the monthly income yet. If you do need it every month, the first three lines are your number and the RD section simply stays empty.
Post Office RD calculator: the RD side on its ownClosing early, worked through
Close the same ₹9 lakh account after 30 months and the post office deducts 2% of the deposit, ₹18,000, so ₹8,82,000 comes back. The monthly interest already paid is yours to keep: 30 payouts of ₹5,550, or ₹1,66,500. Wait until month 36 and the deduction halves to 1%.
What the sheet does not do
- It does not split interest between joint holders for tax. Each holder pays tax on their share.
- It assumes the rate you enter holds for all five years, which is how the scheme works for an account already open. A new account opened next quarter may get a different rate.
- Senior citizens may get more from the Senior Citizens' Savings Scheme, which pays quarterly at a higher rate; this sheet is only for MIS.
Frequently asked questions
- How much monthly interest does Post Office MIS pay on ₹9 lakh?
- At 7.4% a year, ₹5,550 a month, or ₹66,600 a year. A joint account can hold up to ₹15 lakh.
- Can I close Post Office MIS before 5 years?
- Yes, after the first year. Closing between one and three years costs 2% of the deposit; between three and five years, 1%. Interest already paid is not taken back.
- Is Post Office MIS interest taxable?
- Yes. It is added to your income and taxed at your slab, and MIS gets no 80C deduction.
- Does the sheet work in Google Sheets?
- Yes. Upload the .xlsx to Google Drive and open it with Google Sheets; the formulas carry over.