How much should I spend on a car in SA? (The 20% Rule)
When shopping for a car, there are more than just the monthly instalment to consider. You have to factor in the total cost of ownership. Not to mention that financial lenders will only approve a loan if you can afford it. Find out more in this article, where we break it all down.
Buying a car is one of the biggest financial decisions South Africans make, yet many people drive off the lot without ever doing the math. With the average new vehicle price sitting at approximately R500 000, and the average used car selling for around R417 584 in 2025 (AutoTrader Annual Car Industry Report, 2025), the question of affordability has never been more relevant.
Related: Car affordability calculator: How much can you really afford?
So how do you know what you can really afford? Enter the 20% Rule. So before you start your search for new or used models on AutoTrader here, let us help you do some maths and find out just how much you should budget for. You can also sell your car quickly and easily on our website here to get a deposit ready.
What is the 20% rule?
A widely recommended guideline is that your total monthly vehicle-related costs should not exceed 20% of your net (after-tax) monthly income. This isn't just your monthly repayment; it includes your insurance premium, fuel, maintenance, and any other running costs. The logic is simple: keep your car costs manageable enough that they don't crowd out other essential expenses like rent, groceries, savings, and retirement contributions.
What does this look like in practice?
Let's put real numbers to it. According to Statistics South Africa (Stats SA), the average monthly employee earnings in May 2024 were R27,450 gross. After tax, a single earner in that bracket takes home approximately R22 000–R23 500 per month (depending on deductions).
Applying the 20% Rule:
Earner A – R22 000 net/month: Maximum car-related spend shouldn't exceed R4 400/month. This could cover a modest second-hand vehicle priced between R100 000 and R120 000, financed over 60 months at a realistic interest rate of 12.25%, plus basic insurance and some fuel.
Earner B – R35 000 net/month: Maximum car-related spend shouldn't exceed R7 000/month. This opens the door to a vehicle in the R200,000 range, think a Suzuki S-Presso or a Renault Kwid, with comprehensive insurance and some fuel included.
Earner C – R60 000 net/month: Maximum car-related spend shouldn't exceed R12 000/month. This should cover the cost of a new compact SUV like the Toyota Corolla Cross (R420 700) or a Chery Tiggo 7 (R429 900) on a 60-month finance agreement, with insurance and some fuel factored in.
The hidden costs most buyers ignore
King Price Insurance warns that many buyers make the costly mistake of factoring in only the monthly instalment, while ignoring comprehensive insurance (often mandatory for financed vehicles), fuel, tyres, servicing, and toll fees. These costs can easily add R3,000–R5,000+ per month to your repayment, blowing your budget before you know it.
The 20/4/10 formula
For those who want an even stronger framework, some experts will recommend the 20/4/10 Rule. This is where you put down a 20% deposit, the finance period is no more than 4 years, and you keep your total transport costs, including fuel, insurance and maintenance, below 10% of your gross income. This approach significantly reduces the interest you pay over the period of the loan and prevents you from owing more than the car is worth.
The bottom line
The 20% Rule is a practical, well-supported starting point for any South African car buyer. Before signing a finance agreement, calculate your net income, total all ownership costs, and ensure they stay within budget. In a market where vehicle prices have surged, and living costs remain elevated, disciplined budgeting isn't just good advice, it's financial survival.
