What is the VAT Formula?
At its core, the VAT formula represents a basic percentage calculation based on the standard 15% rate set by SARS. Value-Added Tax is designed as a multi-stage tax levied on the value added at each step of the production and distribution chain. To understand how this fits into broader tax rules, read our introductory guide on What is VAT in South Africa.
The mathematical relationship between the price before tax (VAT Exclusive), the tax portion itself (VAT Amount), and the final total price (VAT Inclusive) is represented by three basic components:
- Base Value (VAT Exclusive): The original cost of the product or service before tax is added. This is the amount a business records as its actual revenue or expense in its profit and loss statement.
- Tax Rate: The standard SARS tax factor of 0.15 (equivalent to 15%).
- Total Value (VAT Inclusive): The final cost paid by the end-consumer at the cash register or B2C checkout point.
Under Section 65 of the South African VAT Act, any price advertised or quoted by a registered VAT vendor must include VAT, unless the quote is clearly split to show the exclusive price, the VAT amount, and the inclusive total. This means that as a consumer, the price you see on shelves is always the VAT Inclusive amount. However, businesses registered as VAT vendors must look past this total to identify the underlying exclusive price and tax portion, as they are entitled to claim the tax back from SARS.
VAT Inclusive Formula (Adding VAT)
The vat inclusive formula is used when you know the base cost of an item excluding tax and need to add VAT to a price to determine the final invoice total. This is standard practice for businesses that list prices exclusive of tax for other business clients (B2B transactions), where the final invoicing must reflect the addition of standard 15% tax.
Understanding this formula is vital for preparing tax invoices that comply with SARS guidelines. Under the South African tax system, when you charge VAT, you are acting as an agent for SARS, collecting this output tax on their behalf. You must display the base value, the tax portion, and the final inclusive total clearly on your tax invoices — make sure you read our guide on VAT Invoice Requirements to ensure your invoices are fully compliant.
The Mathematical Formulas:
To calculate the VAT portion alone starting from a VAT-exclusive price, multiply the base value by the standard tax rate of 15% (0.15):
To calculate the final VAT-inclusive total price directly, multiply the exclusive base by 1.15. This multiplier represents 100% of the base value plus the 15% tax component:
Step-by-Step Worked Example:
Suppose your Durban-based consulting agency delivers a training session. The agreed-upon service rate is R8,000 before tax. To calculate the invoice total:
- Identify the base value:
R8,000. - Calculate the 15% VAT portion:
R8,000 × 0.15 = R1,200. This is the Output VAT you will report to SARS. - Calculate the total inclusive price:
R8,000 × 1.15 = R9,200. This is the total amount the client owes you. - Verify the total by summing the base and the tax portion:
R8,000 + R1,200 = R9,200.
VAT Exclusive Formula (Removing VAT)
The vat exclusive formula is applied when you know the final retail price (inclusive of VAT) and need to strip away the tax component. This is essential when recording raw business purchases, as you must separate the base expense from the claimable input tax. You can use our specialized remove VAT from an amount calculator to perform this instantly.
When a business registered as a VAT vendor buys goods or services for business operations, the tax paid is called Input VAT. You can deduct this Input VAT from the Output VAT you have collected on your sales, paying only the net difference to SARS. To do this, you must analyze your supplier receipts and apply the exclusive formula to find the base purchase price and the exact tax portion paid.
The Mathematical Formula:
To find the original cost excluding VAT from a VAT-inclusive total, divide by the tax factor (1.15):
Step-by-Step Worked Example:
You purchase corporate stationery for your office. The cash register receipt states the total paid is R1,380 (which includes the standard 15% tax). To find the base cost before VAT was added:
- Identify the inclusive total:
R1,380. - Divide the total by 1.15:
R1,380 ÷ 1.15 = R1,200. - The base price excluding VAT is R1,200. This is the expense amount you record in your books.
- Calculate the VAT portion paid by subtraction:
R1,380 − R1,200 = R180. This is the Input VAT you can claim back from SARS.
VAT Removal Formula & The "Tax Fraction"
If you only need to determine the specific tax portion from a VAT-inclusive receipt without writing out the full exclusive equation, you can use the how to calculate vat formula designed to isolate the tax portion directly. This is useful for fast bookkeeping entries and auditing bank feeds.
The SARS "Tax Fraction" (15/115)
In South African tax law, the fraction 15/115 is officially defined as the tax fraction. Under Section 1 of the VAT Act, the tax fraction represents the ratio of the tax rate to 100 plus the tax rate (i.e., 15 / (100 + 15)). SARS specifies this fraction for calculating the VAT amount included in any tax-inclusive total, eliminating the need to perform a multi-step division and subtraction.
The Mathematical Formula:
Multiply the inclusive total by the tax fraction 15/115 (which simplifies to approximately 0.130435):
Alternatively, write out the formula as:
Notional Input Tax Formula for Second-Hand Goods
A crucial business application of the tax fraction is the calculation of notional input tax. When a registered VAT vendor purchases second-hand goods (such as a vehicle or equipment) from a non-vendor (who cannot charge VAT), the purchasing vendor is allowed to claim a "notional" input tax deduction from SARS. This encourages trade in second-hand assets.
The formula for notional input tax is applied to the purchase price paid:
For example, if you buy a second-hand delivery van from a private individual for R115,000, the notional input tax you can claim is R115,000 × 15/115 = R15,000.
Step-by-Step Worked Example:
Your Cape Town retail store pays an electricity bill of R2,875 inclusive of VAT. To isolate the tax portion to claim as input VAT:
- Take the inclusive total:
R2,875. - Multiply by 15, then divide by 115:
R2,875 × 15 = R43,125;R43,125 ÷ 115 = R375. (Alternatively:R2,875 × 0.130435 = R375.00). - The isolated VAT portion is R375. This is the tax amount you claim on your VAT201 return.
- Verify by calculating the base:
R2,875 − R375 = R2,500. Check:R2,500 × 0.15 = R375.
How to Calculate VAT in Excel Formula
If you run a small business or work as an accountant in South Africa, you likely use Microsoft Excel or Google Sheets to track your finances. Automating your calculations with an excel formula for vat helps prevent human errors and streamlines your bookkeeping.
Assuming your input price is located in cell A2, here are the exact copy-pasteable formulas you need to use:
| Desired Calculation | Excel Formula | Mathematical Explanation |
|---|---|---|
| Add VAT (15%) to an Exclusive Base | =A2*1.15 |
Multiplies the base by 1.15 to add the 15% tax component. |
| Remove VAT (15%) from an Inclusive Total | =A2/1.15 |
Divides the total by 1.15 to find the tax-exclusive base price. |
| Calculate VAT Portion from an Exclusive Base | =A2*0.15 |
Multiplies the base by 0.15 to calculate only the 15% tax amount. |
| Isolate VAT Portion from an Inclusive Total | =A2*(15/115) |
Multiplies the total by the tax fraction to extract only the VAT amount. |
To avoid rounding issues in spreadsheets, wrap calculations in Excel's ROUND function: =ROUND(A2*1.15, 2). This ensures that your rows sum correctly to the final invoice totals. Failing to use ROUND can result in hidden decimal places, causing small summing discrepancies of a few cents on your VAT return.
Practical Business Examples in Rand
Applying standard equations to different types of South African enterprises demonstrates how VAT formulas function across various industries. Below are five practical business scenarios representing typical SARS compliance workflows:
A Durban agency buys 3 office chairs at R1,500 each excluding VAT. The supplier is a registered VAT vendor listing prices exclusive of tax. They need to calculate the invoice total and claimable tax.
Calculation:
- Determine base exclusive total:
3 × R1,500 = R4,500. - Apply the VAT inclusive formula:
R4,500 × 1.15 = R5,175. - The VAT portion is:
R5,175 − R4,500 = R675. The agency pays R5,175 and claims R675 as Input VAT on their next return.
A Gqeberha copywriter completes a project. Registered voluntarily for VAT (as turnover exceeded R120,000), they charge a R12,000 fee and need to add 15% VAT to the invoice.
Calculation:
- Apply the VAT inclusive formula:
R12,000 × 1.15 = R13,800. - The invoice states: Base = R12,000; VAT (15%) = R1,800; Total = R13,800. The R1,800 output VAT must be paid to SARS on eFiling.
A Cape Town boutique sells boots for R2,300 inclusive of VAT. South African retail prices must display inclusive of tax. The owner calculates the base revenue and tax from POS reports to prepare their VAT201 return.
Calculation:
- Apply the VAT exclusive formula:
R2,300 ÷ 1.15 = R2,000. - Isolate the Output VAT portion:
R2,300 − R2,000 = R300. The boutique records R2,000 as net sales revenue and R300 as tax liability.
A contractor in Pretoria completes a foundation for R115,000 inclusive of VAT. They need to claim input tax and cross-reference the subcontractor's calculations to ensure no billing errors. See how to calculate VAT manually.
Calculation:
- Determine base exclusive value:
R115,000 ÷ 1.15 = R100,000. - The VAT portion is:
R115,000 − R100,000 = R15,000. The contractor records R100,000 as capital expense and R15,000 as Input VAT.
A Johannesburg importer brings components worth R50,000 from overseas. The customs duty is 10% (R5,000). They must apply SARS import tax rules on the ATV. Read more about import VAT calculations.
Calculation:
- Find the Added Tax Value (ATV):
Customs Value + Customs Duty = R50,000 + R5,000 = R55,000. - Apply the 15% VAT rate:
R55,000 × 0.15 = R8,250. The importer must pay R8,250 import VAT to clear customs.
Common VAT Formula Mistakes to Avoid
Mathematical errors in tax filing can lead to severe audits, penalties, interest charges, and cash flow strain. Here are the three most common mistakes made when calculating VAT manually:
1. Subtracting 15% Directly to Remove VAT
This is the most common error. If you have an inclusive total of R1,150 and try to remove VAT by multiplying by 0.85 (which represents subtracting 15% directly), you get: R1,150 × 0.85 = R977.50. This is incorrect.
If you calculate 15% tax on R977.50, you get R146.63, which sums to R1,124.13, not R1,150.
The Fix: Always use division. Divide the inclusive amount by 1.15: R1,150 ÷ 1.15 = R1,000. The correct VAT is R150.
2. Rounding Each Line Item vs. Rounding the Total
If you list multiple items on an invoice, rounding each line item to the nearest cent before summing them up can result in a different total than calculating VAT on the sum of the exclusive prices. SARS allows both methods, but you must apply your chosen method consistently across all invoices to prevent discrepancy issues during reconciliation audits.
3. Misapplying Formulas to Exempt or Zero-Rated Sales
Not all goods carry the standard 15% rate. If you sell basic foodstuffs like brown bread, milk, or eggs, these are zero-rated. Applying the 1.15 formula to zero-rated or exempt items means you will overcharge customers or overpay SARS. Always consult our list of zero-rated VAT items before running your calculations.
VAT Formula vs. VAT Calculator
Should you use mathematical equations or an online tool? Both have their place in business operations:
| Aspect | Using the Manual Formula | Using an Online Calculator |
|---|---|---|
| Speed | Slower; requires manual key inputs and calculator operations. | Instant; enter the value and see all results split immediately. |
| Integration | Essential for writing Excel formulas, scripting spreadsheets, or coding custom software. | Great for quick checks and double-checking invoices on the fly. |
| Risk of Error | Higher; typing errors or formula selection errors can happen. | Minimal; formulas are hard-coded and validated for accuracy. |
For everyday operations, using our main VAT Calculator home tool is the safest and fastest way to ensure your values are mathematically correct and compliant with SARS rules.
Frequently Asked Questions (FAQs)
What is the standard VAT formula in South Africa?
The standard VAT formula in South Africa is: VAT Amount = Base Exclusive Price × 0.15. To find the inclusive price directly, use: Total = Base Price × 1.15.
How do you calculate 15% VAT on a price?
To calculate the VAT portion, multiply the exclusive price by 0.15. For example, if a service is R5,000 before tax: R5,000 × 0.15 = R750 VAT.
What is the formula to remove VAT from a total?
To remove VAT, divide the inclusive total by 1.15. For example, if a product is R230 including tax: R230 ÷ 1.15 = R200 exclusive price.
How do you find the VAT amount from a VAT-inclusive price?
You can find the VAT portion by multiplying the inclusive price by (15/115) or by subtracting the exclusive price from the total: VAT Amount = Total − (Total ÷ 1.15).
Why can't I just subtract 15% to remove VAT?
Subtracting 15% directly from the total gives the wrong mathematical result because the tax was originally calculated on the smaller base price. You must use the division factor of 1.15 to strip the tax accurately.
What is the formula to add VAT?
The formula to add VAT is: Inclusive Price = Exclusive Price × 1.15. This adds the standard 15% tax component directly to the base price.
How do you calculate VAT in Excel?
In Excel, use the formulas:
- To add VAT:
=A1*1.15 - To remove VAT:
=A1/1.15 - For VAT portion only:
=A1*0.15
What is the difference between zero-rated and exempt VAT?
Zero-rated items are taxed at 0%, allowing businesses to claim back input VAT on related costs. Exempt items fall outside the tax net entirely, meaning no input tax can be claimed on related business expenses.
How is import VAT calculated in South Africa?
Import VAT is calculated by customs at 15% on the added sum of the customs value plus customs duties. Formula: Import VAT = (Customs Value + Duty) × 0.15.
What is the current compulsory VAT registration threshold?
The compulsory registration threshold is R2.3 million in taxable turnover over any rolling 12-month period. Learn more about the requirements in our comprehensive VAT Registration guide.
What is the voluntary VAT registration threshold?
The voluntary registration threshold is R120,000 in taxable supplies in a rolling 12-month period. For details on how to apply voluntarily, read our VAT Registration guide.
What is input VAT vs output VAT?
Output VAT is the tax you collect on sales. Input VAT is the tax you pay on expenses. Businesses pay the net difference (Output VAT − Input VAT) to SARS.
Can a business charge VAT without registering?
No, charging VAT or issuing tax invoices showing VAT without being a registered vendor with SARS is a serious criminal offense in South Africa.
How often do you submit VAT returns to SARS?
VAT returns are typically submitted bi-monthly (every two months) using form VAT201 via the online SARS eFiling portal.
How do you do a reverse VAT calculation?
A reverse VAT calculation reconstructs the base exclusive amount starting only from the tax portion. Formula: Base Exclusive Amount = VAT Amount ÷ 0.15.
What is the tax fraction in South Africa?
In South Africa, the standard tax fraction is 15/115. It is a mathematical ratio used to determine the VAT portion included in a VAT-inclusive price without having to first calculate the exclusive base. The formula is: VAT Amount = Inclusive Price × (15/115).
How do you calculate notional input tax on second-hand goods?
Registered VAT vendors can claim notional input tax when purchasing second-hand goods from non-vendors (private individuals). The calculation uses the tax fraction: Notional VAT = Purchase Price × (15/115). The claim must be supported by a completed SARS VAT264 form, proof of payment, and seller identification.
SARS Compliance Tip: Notional VAT Documentation
To claim notional input tax on second-hand goods, vendors must maintain strict documentation. You must complete a SARS VAT264 form detailing the seller's ID, transaction date, description of goods, and proof of payment. Note that the claim is generally limited to the payment actually made and can only be claimed once the purchase price has been paid. For complex transactions, refer to the official SARS guidance or consult a qualified tax professional.