GST Interest Calculator
Compute interest on delayed GST tax payment u/s 50
Calculate interest on delayed GST liability under Section 50 — 18% p.a. on net cash payment, 24% p.a. on wrongly availed ITC. Day-accurate, audit-ready.
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What is a GST Interest Calculator?
Section 50 of the CGST Act mandates interest at 18% per annum on tax paid late and 24% per annum on Input Tax Credit wrongly availed and utilised. The interest accrues from the day after the due date till the date of actual payment, computed on the net cash component of the liability.
After the 2021 amendment (Section 50(1) proviso), interest is calculated only on the net tax liability — i.e. the portion paid in cash through the electronic cash ledger — not on the gross output tax. This single change cut interest bills by 30–60% for most filers.
This calculator handles both rates, supports multiple periods of default in one shot, and shows the day count, daily accrual, and total interest broken down by CGST/SGST/IGST so you can post the exact entries in your books and the cash ledger.
Why use this GST Interest Calculator
Built for Indians, by Indians. Every number, every formula, every slab — tuned to FY 2026-27 reality.
Day-accurate accrual
Counts days from due date + 1 to payment date — leap years handled.
Both rates supported
18% for delayed cash tax; 24% for wrongly availed-and-utilised ITC.
Net cash basis
Applies the post-2021 amendment: interest on net cash, not gross output.
CGST/SGST/IGST split
Output mirrors the cash-ledger payment columns for direct posting.
Using the GST Interest Calculator in 4 steps
No onboarding, no signup. Answer three fields and the numbers update live.
Enter the tax amount
Use the net cash component (output tax less ITC actually utilised) in CGST/SGST/IGST.
Pick due date and payment date
Due date for GSTR-3B is usually the 20th of the following month. Calculator counts delay days.
Choose 18% or 24%
18% for genuine delay; 24% only if ITC was wrongly claimed and utilised.
Read the interest
Pay through DRC-03 or alongside the next GSTR-3B. Save the working as audit support.
Tips to get the most out of it
Interest cannot be paid via ITC — only via cash ledger. Plan working capital accordingly.
Interest on wrongly availed but not utilised ITC was contentious; current settled view (post-2022 amendment) is no interest if ITC was reversed before utilisation.
For self-assessed defaults, pay tax + interest via Form DRC-03 voluntarily. This typically prevents Section 73/74 notices and limits any penalty exposure.
For periods spanning across rate changes (rare but happens with amnesty), split the calculation into pre and post change windows.
Interest is fully deductible as a business expense under Income Tax, unlike penalty (which is disallowed). Code it correctly in your P&L.
Real-world scenarios
How Indians actually use this calculator — concrete inputs, concrete outcomes.
GSTR-3B paid 45 days late
Net cash tax ₹2 L, delay 45 days, rate 18% → ₹2,00,000 × 18% × 45/365 = ₹4,438. Pay via cash ledger before filing.
Wrongly claimed ITC, utilised
Wrong ITC ₹50,000 utilised in May, reversed in November (180 days) → ₹50,000 × 24% × 180/365 = ₹5,918 interest u/s 50(3).
Long-pending audit demand
Officer demands ₹3 L tax for FY 22-23, paid in May 2026. Days from 21-Feb-2024 to 31-May-2026 ≈ 830 days. Interest = ₹3,00,000 × 18% × 830/365 = ₹1,22,795.
Frequently Asked Questions
Still have a question? Our team replies within a business day.
On the net cash liability (post 2021 amendment to Section 50). Earlier circulars demanded interest on gross output tax — that view is now overruled. ITC actually utilised reduces the base.
No. Interest, late fee, and penalty are all payable only through the electronic cash ledger. ITC cannot be used.
24% p.a. under Section 50(3), but only when the ITC has been availed AND utilised. If you reversed it before utilisation, the recent CBIC clarification says no interest applies.
From the day immediately after the due date till the date the tax is debited from the cash ledger (not the date of return filing, if filed earlier or later).
Yes — interest paid for delayed payment of GST is treated as compensatory and is allowable u/s 37(1). Late fee and penalty are not.
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