Savings & interest
Savings goal monthly contribution
Find the monthly deposit required to reach a chosen future savings goal from an existing balance and assumed interest.
Your inputs
Complete the fields for your selected method. Zero means intentionally zero, not unknown. Currency selection labels amounts; it does not convert exchange rates.
How this calculation works
required deposit = max(0, target - grown starting balance) / monthly contribution accumulation factor
A constant-rate arithmetic scenario, not a forecast or promised return. Supply your own return assumptions; example rates are not recommended investments. Monthly contributions are fixed nominal amounts, not automatically increased for inflation. No taxes, contribution limits, account eligibility, trading costs or benefits are inferred. Negative returns are supported; actual return sequences can differ materially. A goal already covered by the projected starting balance requires no additional deposits in this model. This does not assess whether the assumed investment risk suits the goal.
What information do I need?
Use records for the same job, equipment or accounting period. Only the fields for your selected entry method are required. An unknown amount is not zero.
Input definitions and where to find them
- Current balance allocated to this goal (selected currency): The balance already available at the start, not future contributions.
- Target future balance (selected currency): The amount you want at the end, on the stated nominal or today-money basis.
- Projection length entry: Use matching records or a clearly stated assumption for the indicated period. Prefilled figures are illustrative. An unknown value is not zero.
- Years to project (years): Use matching records or a clearly stated assumption for the indicated period. Prefilled figures are illustrative. An unknown value is not zero. Used with: Whole years.
- Months to project (months): Use matching records or a clearly stated assumption for the indicated period. Prefilled figures are illustrative. An unknown value is not zero. Used with: Whole months.
- How is your assumed annual growth rate stated?: Use matching records or a clearly stated assumption for the indicated period. Prefilled figures are illustrative. An unknown value is not zero.
- Your assumed annual growth rate (%): Supply an assumed annual rate on the selected basis. Use effective annual growth or APY unless you specifically have a nominal rate and compounding frequency. The example is not a current quote or forecast.
- Compounding frequency for nominal rate: Use matching records or a clearly stated assumption for the indicated period. Prefilled figures are illustrative. An unknown value is not zero. Used with: Nominal annual rate with stated compounding.
- When is each monthly contribution added?: Use matching records or a clearly stated assumption for the indicated period. Prefilled figures are illustrative. An unknown value is not zero.
Use the Where to find this value controls beside the inputs for available work-it-out helpers. Estimates remain your assumptions; a helper does not verify the source figures.
Worked example
Example amounts use US dollars (USD).
Example answer: Required monthly contribution is $128.64 for the illustrative inputs below.
Example inputs
- Current balance allocated to this goal: $1,000.00
- Target future balance: $10,000.00
- Projection length entry: Whole years
- Years to project: 5 years
- How is your assumed annual growth rate stated?: Effective annual return or APY
- Your assumed annual growth rate: 5.00 %
- When is each monthly contribution added?: End of month
- Required monthly contribution
- $128.64
- Future goal entered
- $10,000.00
- Projected balance at solved contribution
- $10,000.00
- Starting balance plus contributions
- $8,718.54
- Modeled growth toward goal
- $1,281.46
- The target is future nominal money. Contributions are solved at full precision; rounding each deposit to cents can leave a small target difference.
These illustrative values are not recommended rates or industry averages. Replace every example input with your own figures.
Use the result well
Find the monthly deposit required to reach a chosen future savings goal from an existing balance and assumed interest.
Keep inputs on the same scope and time basis. Calculations retain precision internally; displayed values generally round to two decimal places, with extra precision for very small values and whole-unit rounding where required. Economic comparisons describe your supplied assumptions and do not guarantee future results.
This tool provides business arithmetic. It does not approve engineering designs, establish legal or tax treatment, select equipment or certify safe operating conditions.