Rechnerpilot Calculator

Overnight Deposit Calculator

Calculate overnight deposit interest with promotional rates, interest crediting intervals, and capital gains tax. With calculation steps and progress table.

Available

Inputs

Enter values

Live

Investment amount

€

The amount deposited in the overnight account.

Duration in months

Investment duration in months.

Regular interest rate p.a.

The regular annual rate. Model assumption: ACT/360; actual interest calculation follows the contract and terms, and other day-count conventions may produce different results.

Promotional rate p.a.

Higher interest rate during the promotional period.

Promotional duration (months)

Duration of the promotional rate in months.

Interest crediting

How often is interest credited?

Tax treatment

Optional consideration of capital gains tax.

Saver's allowance

€

Annual tax-free allowance (EUR 1,000/person, EUR 2,000/couple).

Church tax

Church tax rate depending on federal state.

Load example

For illustration only – your own calculation is what counts.

Explanation

How Overnight Deposit Calculator works

The overnight deposit calculator computes interest for an overnight money investment with an optional promotional rate. It accounts for different interest crediting intervals and capital gains tax.

Overnight deposit interest (ACT/360)Interest = Capital x Rate x Days / 360

ACT/360 is this calculator's model assumption. Actual interest calculation follows the contract and terms; results may differ under another day-count convention.

Knowledge

Understanding overnight deposits

Basics, advantages, and typical conditions of overnight deposit accounts.

Overnight deposit is a savings product available daily with variable interest. Unlike fixed deposits, money can be withdrawn at any time, but the interest rate is usually lower.

Available daily without notice period.
Variable interest rate — can change at any time.
Deposit insurance up to EUR 100,000 per person and bank.
Promotional rates attract new customers but apply only temporarily.
Ideal as emergency fund or parking spot for short-term money.

Knowledge

Promotional-rate hopping

Which contract details to check with time-limited promotional rates.

Promotional rate, promotional period, the subsequent interest rate and the participation conditions differ by provider and offer. Whether switching accounts is worthwhile cannot be determined from a flat investment amount or a fixed switching interval; the calculator does not compare products.

Practice

Practical examples

For illustration only – your own calculation is what counts.

EUR 10,000, 2.5% p.a., 12 months

EUR 10,000 is invested as overnight deposit for 12 months at 2.5% p.a. How much interest accrues?

Result: After 12 months, interest of approx. EUR 250 accrues with monthly crediting.

1.5% interest rate€10,151.04

2.5% interest rate€10,252.88

3.5% interest rate€10,355.67

EUR 20,000 with 3.5% promotional rate for 6 months, then 1.5%

EUR 20,000 overnight deposit with 3.5% promotional rate for 6 months and 1.5% regular rate for another 6 months.

Result: Promotional phase approx. EUR 350, subsequent phase approx. EUR 150. Total interest approx. EUR 500.

With promotional rate€25,696.17

Without promotional rate€25,504.61

EUR 15,000, 3%, with capital gains tax

EUR 15,000 overnight deposit at 3% with capital gains tax consideration and EUR 1,000 saver's allowance.

Result: Gross interest approx. EUR 450, of which EUR 1,000 is tax-free. Taxable earnings: EUR 0 (below allowance).

EUR 15,000 overnight deposit, 0.5% interest, 30 days

EUR 15,000 balance in an overnight deposit account with 0.5% interest over 30 days.

Result: Overnight deposit interest: approx. EUR 6.25 for 30 days. On an overnight deposit account at 2%, it would be approx. EUR 25.

EUR 20,000, 2.5%, quarterly crediting, 1 year

EUR 20,000 overnight deposit at 2.5% with quarterly interest crediting over 1 year.

Result: After 1 year: approx. EUR 20,503. Quarterly crediting brings a minimal compound interest advantage compared to annual crediting.

Notes

Common mistakes

Assuming the promotional rate is permanent
Promotional period, subsequent rate and eligibility depend on the offer. Do not apply the promotional rate beyond its contractual period.
Enter the promotional rate, its duration and the regular rate separately according to the offer.
Exceeding the deposit insurance limit
Statutory deposit insurance only protects up to EUR 100,000 per person and bank. Anyone investing more carries a default risk. With larger amounts, spread across multiple banks.
Distribute amounts over EUR 100,000 across multiple banks to utilize full deposit insurance.
Not considering the real interest rate
A 2% nominal rate with 3% inflation equals an exact real return of about -0.97%; subtracting to -1% is only an approximation.
Use (1 + nominal return) / (1 + inflation rate) - 1. This calculator does not adjust for inflation.
Ignoring interest crediting timing
Interest calculation, crediting and withdrawal effects follow the contract. Annual crediting does not generally mean no interest is owed before year-end.
Check the contractual calculation and crediting method. The calculator models only the selected interval, not individual contract effects.
Incorrectly splitting saver's allowance across multiple accounts
The saver's allowance of EUR 1,000 applies per person across all banks combined. Those who have overnight deposit accounts at multiple banks must distribute exemption orders accordingly — otherwise withholding tax is deducted unnecessarily.
Keep track of all exemption orders and ensure the total does not exceed EUR 1,000 (EUR 2,000 for couples). Submit a tax return if necessary to reclaim excess deductions.

FAQ

Frequently asked questions

What is a promotional rate for overnight deposits?

A promotional rate is an elevated interest rate that banks offer new customers for a limited period (e.g., 3-6 months). Afterward, the regular, usually lower rate applies. The calculator computes both phases separately.

How often is overnight deposit interest credited?

Interest crediting occurs monthly, quarterly, or annually depending on the bank. Monthly crediting leads to a slightly higher yield due to the compound interest effect.

Is overnight deposit safe?

Overnight deposits are protected by statutory deposit insurance up to EUR 100,000 per person and bank. It is one of the safest forms of investment in Germany.

Why does the calculator use ACT/360?

ACT/360 is this calculator's model assumption: actual calendar days are divided by 360. Actual interest calculation follows the contract and terms; another day-count convention may produce a different result.

What happens after the promotional rate expires?

The rate after a promotional period depends on the offer and terms. The calculator uses only the entered regular rate and gives no switching or product recommendation.

How does overnight deposit differ from fixed deposit?

Overnight deposits are available daily but have a variable interest rate. Fixed deposits offer a fixed, higher rate, but the money is locked for the agreed term. Overnight deposits are suitable for emergency reserves, fixed deposits for medium-term investment.

Do I need to pay tax on overnight deposit interest?

Yes. Overnight deposit interest is capital income subject to capital gains tax (26.375%). The saver's allowance (EUR 1,000/person) remains tax-free. An exemption order at the bank ensures the allowance is automatically applied.

How large should the emergency fund in an overnight deposit account be?

A rule of thumb is 3-6 net monthly salaries as an emergency fund. This should be kept in an overnight deposit account since it must be available at all times. Amounts beyond that can be invested for higher returns.

Limits

Limitations

Interest rate can change at any time: Overnight deposit rates are variable. The bank can adjust the rate at any time. The calculation assumes a constant rate over the specified duration.
No account switching costs considered: Costs and effort for account switching with promotional rate hopping are not factored in.
Simplified tax calculation: Church tax and the lower-rate assessment are not modeled. Actual tax burden may differ.
No product comparison: The calculator calculates interest for given parameters but does not compare current offers from different banks.

Sources

Sources and references

§ 1 KWG — EinlagengeschäftBundesministerium der Justiz
Legal definition of deposit business, under which overnight deposit accounts fall as demand deposits.
View sourceRetrieved: 07/23/2026 · Verified on: 07/23/2026 · Primary source
Einlagensicherungsgesetz (EinSiG)Bundesministerium der Justiz
Legal basis for deposit insurance up to EUR 100,000 per person and bank in Germany.
View sourceRetrieved: 07/23/2026 · Verified on: 07/23/2026 · Primary source
Deutsche Bundesbank — Zinssätze für EinlagenDeutsche Bundesbank
Current average interest rates for overnight deposits at German banks.
View sourceRetrieved: 07/23/2026 · Verified on: 07/23/2026 · Primary source
Verbraucherzentrale — Tagesgeld RatgeberVerbraucherzentrale Bundesverband
Independent consumer information on overnight deposit accounts, promotional rates, and deposit insurance.
View sourceRetrieved: 07/23/2026 · Verified on: 07/23/2026

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