Monthly Savings Calculator: How Much to Save to Reach Your Goal

The monthly savings calculator answers a simple but structuring question: how much must you save each month to reach a given capital, over a set period, at an assumed return? It turns an abstract goal into a concrete monthly effort, compounding included. Its main lesson: the horizon matters more than the return — each extra year cuts the effort far more than one extra point of performance. Further on this: how much you need to save for retirement realistically.

The formula

The calculation uses the constant-annuity formula: the periodic payment needed to reach a target capital, accounting for compounding.

M = C × r / ((1 + r)ⁿ − 1)

• M = required monthly saving
• C = target capital
• r = rate per period (annual rate ÷ 12)
• n = number of payments (years × 12)

When the return is zero (r = 0), the formula simplifies to M = C / n: the target is reached by contributions alone, without compounding.

Example: reaching €50,000 in 10 years

A €50,000 goal — say a property down payment — over 10 years, at an assumed 4% annual return. Monthly rate r = 0.04 / 12 ; payments n = 120. The result is about €341 / month. Over 10 years, contributions total ≈ €40,900 ; the rest (≈ €9,100, i.e. 18% of the final capital) comes from compounding. Without return, it would take €417 / month — €76 more each month.

Impact of horizon and return

Amount to save each month to reach €50,000, by horizon and annual return.

Two levers stand out. The horizon: going from 10 to 20 years halves the effort — or thirds it at 6%. The return, whose effect amplifies over time. This is exactly what the simulator’s curve shows: the gap between the “with return” and “without return” curves is what compounding saves you in effort. On a related note, see why time is the most underestimated variable in finance.

Monthly savings simulator

Indicative, educational results. They constitute neither investment advice, a personalized recommendation, nor an inducement to use a specific financial product.

Which tool for your question

This calculator starts from a final goal and works back to the monthly effort: “How much to set aside each month to reach this amount?” If your question is the reverse — “What capital can I build by saving €X per month?” — the compound interest calculator projects a capital from regular contributions.

The three parameters that set the effort

The horizon: the most powerful lever

Extending the horizon cuts the monthly effort most, through the mechanics of compounding: the final years concentrate a disproportionate share of the gains. Adding 5 years to a horizon can reduce the payment by 30 to 40%.

The assumed return: prudence and realism

An over-optimistic return artificially lowers the displayed effort and creates a false sense of security. Over 10 to 20 years, net real returns — after inflation and taxes — have historically sat between 2% and 5% depending on asset class. A prudent rate produces more robust projections.

Contribution regularity

The model assumes constant contributions, without interruption. Pausing for 12 months does not just delay the goal by 12 months: the loss is amplified by the missing compounding on the amounts not contributed.

Limits and precautions

Inflation is not included: €50,000 today will not have the same purchasing power in 20 years — see the real return after inflation simulator. Taxes and fees are not modelled: depending on the wrapper, the effective net differs from the gross. Finally, a constant return is an assumption: markets vary. The projection is a framing estimate, not a forecast.

Frequently asked questions

How much to save per month for €100,000?

It depends on horizon and return. At 4%: ≈ €682/month over 10 years, €407 over 15 years, €272 over 20 years. Without return: €833, €556, €417. The simulator lets you test your own scenario.

What return should I use?

A prudent return (2 to 5% depending on horizon and vehicle) gives the most realistic projections. A regulated savings account: 2 to 3%. A diversified portfolio over 15 years and more: 4 to 5% remains reasonable on historical data — with no guarantee of future results.

Better to save more over a short period or less over a long one?

The long horizon is almost always more efficient. Saving €200/month for 25 years at 4% produces ≈ €103,000 ; €400/month for 10 years at the same rate, ≈ €59,000. The total effort is close (€60,000 vs €48,000 contributed), but the result differs by ≈ €44,000 in favour of duration.

How do I include a starting capital?

Enter it in the capital already saved field: the tool projects its future value, then computes the monthly effort only on the remaining balance. If the starting capital is enough, the tool says so.

Does the tool account for inflation?

No, amounts are in nominal euros. With 2% inflation, a 4% nominal return corresponds to ≈ 2% real — which reduces the purchasing power of the final capital. See the real return calculator.

Key takeaways

• The tool turns a goal into a concrete monthly effort, compounding included.
• The horizon is the most powerful lever: +5 years can cut the payment by 30 to 40%.
• A prudent return (2 to 5%) yields more reliable projections than an optimistic one.
• Inflation, taxes and fees are not included: the result is an order of magnitude, not a forecast.

Last updated — 12 July 2026