Understanding your GST results
The selectable rates correspond to published national GST structures. Slab assignment for specific items follows official notifications and changes over time.
| Rate | Context |
|---|---|
| 5% | India — many essentials and mass-consumption items |
| 12% / 18% | India — the two standard slabs covering most goods and services |
| 28% | India — luxury and sin goods, some with additional cess |
| 10% | Australia — single standard rate since 2000 |
| 15% | New Zealand — single broad-based rate |
- India's slab assignments are decided by the GST Council and revised periodically; CBIC notifications are the authoritative source for the current rate on any item, and some goods carry an additional compensation cess not modeled here.
- The CGST/SGST split shown applies to Indian intra-state supplies; inter-state supplies attract IGST at the full rate instead — the total tax is the same.
- Registration thresholds, input-tax-credit rules, invoicing requirements and exemptions are jurisdiction-specific; a qualified tax practitioner or the tax authority should be consulted for business compliance.
What is GST?
Goods and Services Tax (GST) is a value-added consumption tax applied to most goods and services, collected at each stage of the supply chain with credits for tax paid on inputs, so the burden falls on the final consumer. India introduced its GST in July 2017, replacing a patchwork of central and state taxes; Australia has operated a single-rate 10% GST since 2000, and New Zealand a broad-based GST since 1986, currently 15%.
India uses a multi-slab structure set by the GST Council: 5% for many essentials, 12% and 18% as the main standard slabs covering most goods and services, and 28% for luxury and sin goods, with some items exempt or zero-rated. Because slab assignments change through GST Council decisions, the applicable rate for a specific product should be confirmed against current official notifications from the Central Board of Indirect Taxes and Customs (CBIC).
Indian GST splits by transaction geography. On intra-state supplies the tax divides equally into CGST (central GST) and SGST (state GST) — an 18% charge is 9% CGST plus 9% SGST. On inter-state supplies a single IGST (integrated GST) at the full rate applies instead. The consumer pays the same total either way; the split determines which government receives the revenue.
How to use this GST calculator
- Choose the direction: add GST to a net price, or remove GST from a GST-inclusive price.
- Enter the amount — net when adding, gross when removing.
- Select the GST rate: 5%, 12%, 18% or 28% for India, 10% for Australia, or 15% for New Zealand.
- Read the gross amount, the GST amount, and the CGST/SGST halves (relevant for Indian intra-state supplies).
The GST formulas
Adding GST multiplies the net amount by the rate; removing it divides the gross amount by (1 + rate). For Indian intra-state supplies the GST amount splits equally into CGST and SGST.
Worked example (add): ₹1,000 net at 18% carries ₹180 of GST — ₹90 CGST plus ₹90 SGST — for a gross of ₹1,180. Worked example (remove): a GST-inclusive price of ₹1,180 at 18% contains a net of 1,180 ÷ 1.18 = ₹1,000 and ₹180 of GST. Subtracting 18% from ₹1,180 would give ₹967.60 — incorrect, because the 18% was charged on the net.
Common mistakes
- Removing GST by subtracting the percentage from the gross price instead of dividing by (1 + rate).
- Applying 18% to an item that sits in the 5%, 12% or 28% slab — slab assignment is item-specific and changes with GST Council decisions.
- Showing CGST/SGST on an inter-state invoice where IGST applies (or vice versa).
- Forgetting the compensation cess on certain 28%-slab goods such as tobacco and some vehicles.
- Using outdated rates; India's slabs and item assignments have been revised repeatedly since 2017.
الأسئلة الشائعة
How do I calculate GST at 18%?
To add 18% GST, multiply the net price by 0.18 for the tax and by 1.18 for the gross: ₹1,000 net becomes ₹1,180 gross with ₹180 GST. To remove 18% from a GST-inclusive price, divide by 1.18: ₹1,180 gross contains ₹1,000 net and ₹180 GST. For an intra-state supply the ₹180 splits into ₹90 CGST and ₹90 SGST.
What are the GST slab rates in India?
India's GST structure uses four main slabs set by the GST Council: 5% for many essentials, 12% and 18% as the standard slabs covering most goods and services, and 28% for luxury and sin goods (some with an extra cess). Certain items are exempt or zero-rated. Which slab applies to a specific product follows official CBIC notifications and is revised periodically.
What is the difference between CGST, SGST and IGST?
On a supply within one Indian state, the GST charge splits equally: half is CGST (collected by the central government) and half SGST (collected by the state). On a supply between states, a single IGST at the full rate applies and is later apportioned. An 18% intra-state charge is 9% + 9%; the same inter-state supply carries 18% IGST. The buyer pays the same total in both cases.
How do I remove GST from a GST-inclusive price?
Divide the inclusive price by 1 plus the rate: net = gross ÷ (1 + rate). At 18%, ₹1,180 ÷ 1.18 = ₹1,000 net; at 10% (Australia), $110 ÷ 1.10 = $100 net. Subtracting the percentage from the gross overstates the tax removed, because GST is charged on the net amount, not the gross.
What is the GST rate in Australia and New Zealand?
Australia applies a single 10% GST to most goods and services, in place since July 2000, with GST-free categories including most basic food, health and education. New Zealand applies a broad-based 15% GST (raised from 12.5% in 2010) with very few exemptions, a design often cited by the OECD as one of the cleanest consumption-tax bases.
المراجع
- Central Board of Indirect Taxes and Customs (CBIC), Government of India. GST rate notifications and schedules. cbic.gov.in.
- GST Council, Government of India. Rate structure decisions and press releases. gstcouncil.gov.in.
- Australian Taxation Office (ATO). GST — how it works and GST-free supplies. ato.gov.au.
- Inland Revenue (New Zealand). GST rate and registration guidance. ird.govt.nz.
- OECD. Consumption Tax Trends — VAT/GST rates and structures. oecd.org.