Planning
Retirement calculator with pension and spending stages
Project retirement savings with contributions, pension income, changing spending, inflation and withdrawals. Explore simulated balances and shortfall risk.
Content updated . Assumptions reviewed .
Your inputs
Showing the example. Edit your inputs, then calculate.
Projected value
0 USD
Retirement projection with staged expenses, entered pension income and simulated sequence risk.
- Real Value
- 0
- Success Probability
- 0
- Depletion Probability
- 100
- Withdrawal Shortfall
- 2,000
- Contributions
- 0
- Withdrawals
- 10,000
- Fees
- 0
- Taxes
- 0
- P5
- 0
- P25
- 0
- P50
- 0
- P75
- 0
- P95
- 0
Illustrative result from your inputs and the dated assumptions shown; not a forecast, recommendation or offer
KlarFort is not financial, investment, tax, or legal advice. Verify outputs before making material decisions. Read the disclaimer.
Personal and commercial use is free with credit to KlarFort. See usage and credit.
About this calculator
Model saving before retirement and withdrawals afterward within one monthly timeline. Enter pension income and optional life stages to represent periods with different retirement spending or other income.
Compare the constant-return projection with simulations that vary monthly returns. The model includes your fee, tax and inflation assumptions and reports withdrawal shortfalls as well as ending balances.
How to use this calculator
- Enter the starting balance, projection length, monthly saving before retirement and the first retirement month.
- Enter retirement spending, monthly pension and its starting month, with amounts in today's money.
- Add any non-overlapping life stages using inclusive month ranges, spending and other monthly income.
- Set return, volatility, fee, tax, inflation and simulation settings, then calculate and review balances and shortfalls.
Understand your result
The headline is the constant-return ending balance. Real value expresses it in starting-period purchasing power. The percentile results summarize simulated nominal ending balances.
A simulated path succeeds only when every withdrawal is funded and every month ends with a positive balance. The success percentage describes this model and does not estimate your actual future probability of retirement success.
Questions about this calculator
How are retirement and pension months counted?
Month one is the first projection month. Contributions continue before the entered retirement month; retirement spending begins in that month. Pension income begins in its entered month when the model is in retirement.
What does a life stage replace?
During retirement, an active stage replaces the base monthly spending and adds its entered income alongside any pension. Stage start and end months are both included, and stages cannot overlap.
Why can the order of investment returns matter?
Withdrawals reduce the amount left invested after a loss, so later gains may recover less money. The simulations vary monthly returns to illustrate this sequence effect under the entered assumptions.
Where do my figures go?
Your page calculations run in this browser. The API and connected assistants send the inputs supplied to them to our Cloudflare Worker. See Privacy.
How can I reproduce this result?
Use the same inputs and assumptions shown here. Simulation seeds reproduce the same paths. Read the calculation documentation.
Your calculation table
| Month | Balance | Retired |
|---|---|---|
| 1 | 9,000 | Yes |
| 2 | 8,000 | Yes |
| 3 | 7,000 | Yes |
| 4 | 6,000 | Yes |
| 5 | 5,000 | Yes |
| 6 | 4,000 | Yes |
| 7 | 3,000 | Yes |
| 8 | 2,000 | Yes |
| 9 | 1,000 | Yes |
| 10 | 0 | Yes |
| 11 | 0 | Yes |
| 12 | 0 | Yes |
Citable worked example
Retirement calculator with pension and spending stages: fixed public worked-example outputs using the calculator’s published default inputs. Project retirement savings with contributions, pension income, changing spending, inflation and withdrawals. Explore simulated balances and shortfall risk. These illustrative figures are independent of visitor inputs and live market feeds. The table contains 12 rows and is available as CSV and JSON. Formula and assumptions reviewed 2026-09-07.
These are fixed public examples. Your calculation above does not change this table.
| Month | Balance | Retired |
|---|---|---|
| 1 | 9,000 | Yes |
| 2 | 8,000 | Yes |
| 3 | 7,000 | Yes |
| 4 | 6,000 | Yes |
| 5 | 5,000 | Yes |
| 6 | 4,000 | Yes |
| 7 | 3,000 | Yes |
| 8 | 2,000 | Yes |
| 9 | 1,000 | Yes |
| 10 | 0 | Yes |
| 11 | 0 | Yes |
| 12 | 0 | Yes |
Computed with KlarFort Calculators, https://klarfort.com/
Calculator reference: https://klarfort.com/tools/retirement-calculator/. Usage and credit.
Formula and assumptions
Before retirement, contribute monthly. During retirement, withdraw max(inflated expenses − indexed pension − indexed stage income, 0), or invest the surplus. Apply monthly returns, asset fees and tax on positive gains.
- Contributions are made at the beginning of each month. Annual returns are effective rates converted to monthly compound factors. All figures use one entered currency.
- Retirement and pension months are one-based and inclusive. Stage ranges cannot overlap. All retirement expense, pension and stage income amounts are in today's money and grow with the entered inflation rate.
- Success requires no withdrawal shortfall and a positive balance at every month end, including the final month. Zero-volatility simulations match the deterministic path. Return draws are independent lognormal samples; the model does not estimate actual future probabilities.
Assumptions reviewed:
Sources
- KlarFort calculation methodology. Free to use with the credit line; vintage 1.
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