GST Interest Calculator
Calculate the interest payable on delayed GST payments under Section 50 of the CGST Act. Enter the net tax payable and the number of days the payment was delayed.
The net tax payable amount (output tax minus ITC) for which payment is being delayed.
From the due date of GSTR-3B to the actual date of payment.
Section 50 of the CGST Act prescribes 18% p.a. on net tax liability for late payment.
Important Notes
- Interest is calculated on a simple interest basis (not compound)
- Section 50(1): 18% p.a. on net tax liability for late payment
- Section 50(3): 24% p.a. on ITC wrongly availed and utilised (not covered by this calculator)
- Late fees are separate and not included in this calculation
- This is an estimate — actual interest may be computed differently by the GSTN portal
When is Interest Payable Under GST?
| Section | Situation | Rate |
|---|---|---|
| Section 50(1) | Late payment of net tax liability | 18% p.a. |
| Section 50(1) | Excess ITC claimed or utilised (self-assessed) | 18% p.a. |
| Section 50(3) | ITC wrongly availed and utilised (determined by proper officer) | 24% p.a. |
This calculator covers Section 50(1) — the 18% p.a. rate for late payment of net tax liability. The 24% rate under Section 50(3) applies in more serious cases determined by a proper officer.
How to Calculate GST Interest Manually
The formula for simple interest on delayed GST payment:
Example: If your net tax payable is ₹50,000 and you pay 30 days late:
Interest = ₹50,000 × 0.18 × (30 ÷ 365)
Interest = ₹50,000 × 0.18 × 0.0822
Interest = ₹739.73
Interest is calculated from the due date of the return to the date of actual payment. It is computed on a simple interest basis — no compounding.