Immediate
Full exposure now
Lump Sum vs. Monthly Investing Calculator
Compare investing one available amount immediately with dividing the same amount into monthly investments over a chosen entry period.
Immediate and phased investment paths
Use the same available cash in both paths so the result isolates entry timing rather than contribution size.
Enter your figures, then press “Compare the entry schedules” to calculate your result.
No result yetComplete the fields and use the calculation button.
What this investing timing comparison isolates
The calculator invests the same available amount in two ways. One path enters immediately. The other divides it evenly across the selected months while uninvested cash earns zero in the model.
- Both paths invest the same original amount.
- The model uses a smooth return only to show time-in-market exposure.
- Real market timing can reverse the projected order.
Hold the original amount constant
Both paths begin with the same available cash so the comparison isolates timing rather than a higher saving rate. The phased path does not add new salary contributions.
If the cash earns interest while waiting, the phased result will be understated. Add that consideration separately and include any account or transaction costs.
Understand what the smooth-return model cannot predict
With a constant positive return, investing earlier normally ends higher because more money has more time in the model. Real markets do not rise smoothly, and a decline after entry can make the phased path look better for a period.
The calculator cannot forecast which path will win from today's market level. It shows the cost of delayed exposure under one assumption.
This comparison isolates time in the market
It cannot predict the next market move or decide which implementation you can follow.
Phased
Scheduled entries
Same cash
Fair comparison
Choose a rule that can be completed
Immediate entry may fit a diversified long-horizon allocation and an investor able to accept short-term losses. Phasing may help someone follow the plan without abandoning it after one difficult week.
Write the dates and amounts before starting. Do not extend the schedule repeatedly in response to headlines, because that turns a fixed implementation rule into market timing.
- Same starting cash
- Defined entry period
- Consistent target allocation
- No performance promise
Common questions about this calculator
Does the higher projected path predict which strategy will win?
No. A smooth positive return favors earlier exposure, while real markets move unevenly. The result explains timing under one assumption and cannot forecast entry conditions.
Does the phased cash earn savings interest?
The model assigns zero return to cash waiting to be invested. Include a supportable after-tax cash yield separately if it is material to the decision.