How to Calculate Deposit Interest in Türkiye
Region: TürkiyeHesaplayıcı3 min read
Short answer
Deposit interest is what a Turkish lira time deposit earns in its term. Gross interest is principal × annual rate × days / 365; withholding tax is then deducted. For example, 100,000 TRY at a gross 40% a year for 32 days earns 3,506.85 TRY gross and 2,893.15 TRY net after 17.5% withholding.
Formula
gross interest = principal × annual rate × days / 365
withholding = gross interest × withholding rate
net interest = gross interest − withholding
- principal: the amount deposited
- annual rate: the bank’s gross yearly rate as a decimal (0.40 for 40%)
- days: the length of the term; Turkish banks count a year as 365 days for TL deposits
- withholding rate: the rate in force for the term on the day the deposit is opened or renewed
The final amount is the principal plus the net interest.
Step-by-step example
100,000 TRY at a gross 40% a year, for 32 days, with 17.5% withholding:
- Find the gross interest: 100,000 × 0.40 × 32 / 365 = 3,506.85 TRY.
- Find the withholding: 3,506.85 × 0.175 = 613.70 TRY.
- Find the net interest: 3,506.85 − 613.70 = 2,893.15 TRY.
- Find the final amount: 100,000 + 2,893.15 = 102,893.15 TRY.
The 40% rate in the example is an illustration, not a market rate.
Withholding rate by term
For TL time deposits opened or renewed since 9 July 2025, the withholding rate in Türkiye depends on the term (Presidential Decision 10041, Official Gazette 9 July 2025, no. 32951). The rates are temporary; the latest extension runs to 31 December 2026 (Presidential Decision 11444, Official Gazette 20 June 2026, no. 33286):
| Term | Withholding rate |
|---|---|
| Demand deposits and up to 6 months (6 months included) | 17.5% |
| Over 6 months, up to 1 year (1 year included) | 15% |
| Over 1 year | 10% |
The rate is the one in force on the day the deposit is opened or renewed, not the day the interest is paid. The decision defines terms in months and years, not days.
100,000 TRY at a gross 40% a year, for different terms:
| Term | Withholding | Gross interest | Net interest | Final amount |
|---|---|---|---|---|
| 32 days | 17.5% | 3,506.85 TRY | 2,893.15 TRY | 102,893.15 TRY |
| 92 days | 17.5% | 10,082.19 TRY | 8,317.81 TRY | 108,317.81 TRY |
| 365 days | 15% | 40,000.00 TRY | 34,000.00 TRY | 134,000.00 TRY |
| 730 days | 10% | 80,000.00 TRY | 72,000.00 TRY | 172,000.00 TRY |
Common mistakes
- Reading the gross rate as net. The rate the bank quotes is gross. The interest you receive is lower by the withholding.
- Treating renewals as one term. The formula covers one term. If you renew a 32-day deposit with its interest at every maturity, the interest earns interest too; use compound interest for that.
- Forgetting inflation. In the 1-year example, 100,000 TRY becomes 134,000 TRY. Compare that gain with inflation over the same period: according to TurkStat, Turkish CPI rose 31.51% in the year to August 2026, which leaves a real return of about 1.89%.
Worked example: 100,000 TRY at 40% a year for 32 days, 17.5% withholding
Net interest
2,893.15 TRY
- Gross interest
- 3,506.85 TRY
- Withholding tax
- 613.7 TRY
- Final amount
- 102,893.15 TRY
Step by step
Gross interest
gross interest = principal × annual rate × days / 365
gross interest = 100,000 × 40% × 32 / 365 = 3,506.85
Withholding tax
withholding = gross interest × withholding rate
withholding = 3,506.85 × 17.5% = 613.7
Net interest
net interest = gross interest − withholding
net interest = 3,506.85 − 613.7 = 2,893.15
Final amount
final amount = principal + net interest
final amount = 100,000 + 2,893.15 = 102,893.15