Goal seeking
How Much More Per Month If I Start Late?
Same goal, same deadline, but fewer months to contribute usually means a higher monthly amount in a model. Here are illustrative examples and how to test your own timing safely.
Published: December 22, 2025 · Updated: December 22, 2025 · By FinToolSuite Editorial
Run timing scenarios in the calculator
Compare start-now vs start-later under the same goal and assumptions.
Disclaimer
Educational purposes only; not financial advice. Examples are illustrative; real returns vary and investments can go down as well as up. Fees, taxes, inflation, and rules vary by country/provider. Results are planning estimates, not guarantees.
Quick answer
Same goal and deadline with fewer months typically means a higher modeled monthly contribution. Higher assumed returns lower the modeled amount but are not guaranteed.
Monthly contributions explainedWhat stays the same (fair comparison)
- Same goal amount.
- Same deadline/horizon.
- Same return assumption.
- Only the start date changes.
Example 1: £10,000 goal in 5 years (illustrative)
Assumed return: 5% (illustrative). Comparing start now vs start 12 months later.
| Start delay | Months contributing | Estimated monthly amount |
|---|---|---|
| Start now | 60 | ~£147 |
| Start 12 months late | 48 | ~£189 |
Example 2: £25,000 goal in 10 years (illustrative)
Assumed return: 5% (illustrative). Comparing start now vs start 24 months later.
| Start delay | Months contributing | Estimated monthly amount |
|---|---|---|
| Start now | 120 | ~£161 |
| Start 24 months late | 96 | ~£212 |
Example 3: Rate sensitivity (illustrative)
Same £10,000 goal over 5 years, start now vs start 12 months late. Showing low/base/high assumptions to see sensitivity.
| Assumed rate | Start now monthly (est.) | Start 12m late monthly (est.) |
|---|---|---|
| 3% (illustrative) | ~£150 | ~£193 |
| 5% (illustrative) | ~£147 | ~£189 |
| 7% (illustrative) | ~£144 | ~£186 |
Higher assumptions reduce the modeled monthly amounts, but these rates are not guarantees—test ranges.
How to run your own scenarios
- Pick your goal and deadline.
- Run “start now” to get a baseline monthly amount (use the goal monthly amount guide if needed).
- Re-run with later start dates (e.g., +6, +12, +24 months) to see higher monthly amounts.
- Save the scenarios and compare them side-by-side.
What can compensate for a late start?
- Increase the monthly contribution (modeled, not advice).
- Extend the deadline (more months to contribute).
- Test different assumptions (scenario ranges, not guarantees).
FAQ
How much more per month do I need if I start 1 year late?
In Example 1, the monthly amount rises from ~£147 to ~£189 when starting 12 months later. Your numbers will differ—test them.
Does starting late always mean paying more per month?
With the same goal, deadline, and assumptions, fewer months usually mean a higher monthly amount.
What return assumption should I use?
Try low/base/high ranges. Keep the same rate when comparing different start dates for fairness.
What if my contributions aren’t monthly?
You can convert to an equivalent monthly figure to compare timelines or model your actual cadence if your tool supports it.
Does contribution timing (start/end of month) matter?
Slightly. Start-of-month deposits compound a bit longer than end-of-month. Keep timing consistent across scenarios.
Do fees, taxes, or inflation matter?
Yes. They reduce net outcomes. You can approximate by testing a lower net return assumption alongside your baseline.
Are results guaranteed?
No. All outputs are estimates based on assumptions. Real returns can be higher, lower, or negative.
What’s the quickest way to compare multiple start dates?
Run start-now, +12 months, and +24 months with the same goal, deadline, and rate, then save and compare side-by-side.
Next steps
Create three scenarios: start now, start in 12 months, start in 24 months. Keep goal, deadline, and assumptions the same, then compare the modeled monthly amounts.