ArthaSiddhi
Retirement

How the NPS Calculator Builds Your Retirement Corpus

How current corpus, beginning-of-month contributions, monthly compounding and annual contribution increases produce the projected NPS corpus.

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This article is for education and general information. See the Financial Disclaimer before using it for an important decision.

Ages determine the number of modeled months

The engine subtracts current age from retirement age to obtain a whole-year duration, then multiplies that duration by 12. Retirement age must be greater than current age, and both ages must be whole numbers within the calculator's supported range.

The calculator enforces its supported age boundaries, but entering an age does not establish NPS eligibility or an exit entitlement.

Current corpus and each contribution compound monthly

The current corpus is the opening balance. At the beginning of each modeled month, the engine adds that month's contribution and then applies a monthly-equivalent rate equal to the entered annual return divided by 12.

This is a constant projection convention. It does not model daily valuation, unit allocation, asset allocation, charges or actual NPS fund performance.

The contribution steps up after each completed year

The starting monthly contribution remains unchanged for the first 12 contributions. If an annual increase is entered, the engine increases the monthly amount before contribution 13 and after each later completed 12-month block.

Two-year zero-return example showing contribution timing
Starting monthly contributionAnnual increaseModeled monthsTotal contributionsFinal monthly contributionProjected corpus
₹5,000.0010%24₹1,26,000.00₹5,500.00₹1,26,000.00

Projected corpus separates contributed capital from estimated growth

The result reports the starting corpus, total modeled contributions and estimated investment growth separately. Adding those three values reconciles to the projected retirement corpus, subject only to unrounded floating-point precision.

Estimated growth is not an NPS return record or a promise. Changing the assumed return changes the projection rather than predicting a fund outcome.

Return to NPS Explained or review the complete calculator assumptions.

Frequently asked questions

When is each monthly contribution added?

The engine adds it at the beginning of the modeled month before applying that month's return assumption.

How is the monthly return obtained?

The calculator divides the entered nominal annual return by 12. It then uses that constant monthly-equivalent rate throughout the projection.

Does estimated growth represent actual NPS fund performance?

No. It is produced by a constant user-entered assumption and is not current or historical fund performance.