GST Input Tax Credit (ITC) Calculator India — FY 2025-26
Calculate your eligible Input Tax Credit, identify blocked credits under Section 17(5), and reconcile ITC claimed in GSTR-3B with GSTR-2B. Covers Rule 42/43 proportionate reversal, 18% interest on excess claims, and the complete blocked credit checklist. Updated for FY 2025-26 per CBIC guidelines.
Try another scenario
How to Use This Calculator
ITC Calculator tab
Enter your GST on sales (output tax), GST on purchases (input tax), and any blocked credits under Section 17(5). The calculator computes your eligible ITC after Rule 42/43 proportionate reversal and shows your net GST payable. Use the advanced options to specify common credit percentage and exempt turnover ratio.
Blocked Credit Check tab
Select the purchase categories from the checklist to instantly see which are blocked under Section 17(5) and which are fully eligible for ITC. Enter the GST amount for each selected category to get a total blocked vs eligible breakdown. Each blocked category shows its exception (if any) so you can check whether your specific situation qualifies.
ITC vs 2B Reconciliation tab
Enter ITC claimed in GSTR-3B and ITC available in GSTR-2B to identify mismatches. If you have over-claimed, the calculator computes the reversal amount and interest at 18% p.a. under Section 50, based on the months of excess claim. If you have under-claimed, it shows the additional ITC you can still claim.
Share your result
Every input is encoded in the URL. Click Share to send your exact scenario to a CA, colleague, or save for later reference.
The Formula
Input Tax Credit (ITC) is the mechanism that prevents cascading taxation under GST. Businesses can offset GST paid on purchases against GST collected on sales, paying only the net difference to the government.
Net GST Payable = Output Tax (GST on sales) − Eligible Input Tax Credit
Eligible ITC = Total Input Tax − Blocked Credits − Rule 42/43 Reversal
Rule 42/43 Reversal (Common Credits):
Common Credit = Total Input Tax × Common Credit %
Reversal = Common Credit × (Exempt Turnover / Total Turnover)
Eligible Common Credit = Common Credit − Reversal
ITC Reconciliation:
Excess ITC = ITC Claimed in 3B − ITC Available in 2B
If Excess > 0 → Reversal required
Interest = Excess ITC × 18% × (Months / 12)
Key Thresholds (FY 2025-26):
• 100% GSTR-2B matching required (no provisional tolerance)
• Interest on excess ITC: 18% p.a. (Section 50)
• ITC claim deadline: 30 Nov of next FY or GSTR-9 filing date
• E-invoicing mandatory for turnover > ₹5 Cr
The ITC system ensures that tax is paid only on the value addition at each stage of the supply chain. A manufacturer pays GST on raw materials and offsets it against GST collected on finished goods — only the incremental tax reaches the government.
Example
Rahul — IT services company with ₹50 Lakh monthly turnover
Rahul runs an IT services company in Bengaluru. His monthly turnover is ₹50,00,000 and he charges 18% GST on all services. He incurs various business expenses on which GST is paid.
Step 1: Calculate Output Tax
Step 2: Identify Input Tax
Step 3: Blocked Credits
Step 4: Net GST Payable
Rahul pays ₹5,22,000 instead of ₹9,00,000 to the government. The ₹23,000 in blocked credits (food for employees, car insurance) cannot be claimed regardless of business use.
Reconciliation Example
Rahul must reverse ₹18,000 plus ₹810 interest in his next GSTR-3B because one vendor failed to file GSTR-1, so ₹18,000 did not appear in his GSTR-2B.