GuideStation
Sources

Sources & methodology

Where every number in our calculators comes from, when it took effect and when we last checked it. We separate official data from our own assumptions, and label which is which.

Official data

Published by SARS, the SARB or in the law. Each has its source, the date it took effect and the date we checked it.

GuideStation assumption

A planning figure we chose, with our reasoning. Not an official rate.

Rough estimate

A broad rule of thumb for a first idea. Get a quote before deciding.

How we keep official data current

Every official figure has a review deadline tied to when it can change: after each SARB Monetary Policy Committee decision for interest rates, and after each Budget for tax and transfer duty. Our site automatically refuses to publish an update while any official figure is past its review deadline.

Tax

Income tax, credits and deductions published by SARS for each tax year.

Interest rates

The SARB policy rate and the prime lending rate, re-checked after every Monetary Policy Committee decision.

Property

Transfer duty from SARS, plus the estimates our property tools use.

  • Transfer duty rates

    Official data

    0% up to R1 210 000, then 3% to 13% in bands

    In effect from 1 April 2025 · Checked 27 September 2026

    Source: South African Revenue Service, Transfer duty

    Used in: Bond calculator

  • Default bond interest rate

    Calculated

    12.00%

    Calculated from: Prime lending rate and Default bond rate margin above prime

    Used in: Bond calculator, Property affordability

  • Default bond rate margin above prime

    GuideStation assumption

    prime + 1.25 percentage points

    Banks price home loans relative to prime according to the borrower's risk. GuideStation starts the calculators slightly above prime so a first estimate is not optimistic; you can change the rate.

    Last reviewed 27 September 2026

    Used in: Bond calculator, Property affordability

  • Property affordability ratio

    GuideStation assumption

    repayment plus existing debt up to 30% of gross monthly income

    South African banks commonly limit a bond repayment to about this share of gross income. Each bank applies its own affordability assessment, including your living expenses and credit record.

    Last reviewed 27 September 2026

    Used in: Property affordability

  • Bond registration cost estimate

    Rough estimate

    about 1.2% of the bond amount + R5 000

    A simplified approximation of attorney fees and Deeds Office costs for registering a bond. It is not the conveyancers' fee guideline; your attorney's quote will differ.

    Last reviewed 27 September 2026

    Used in: Bond calculator

  • Transfer (conveyancing) fee estimate

    Rough estimate

    about 1% of the price + R8 000

    A simplified approximation of the transferring attorney's fees and Deeds Office costs. Transfer duty is calculated separately from the SARS table.

    Last reviewed 27 September 2026

    Used in: Bond calculator

Retirement assumptions

The Retirement Planner projects in today's rands using these long-run assumptions. They are not official rates.

  • Retirement investment return (after inflation)

    GuideStation assumption

    5% a year after inflation by default, with cautious and growth presets

    A long-run real return for a balanced retirement portfolio. Working after inflation keeps every figure in today's rands. Returns are not guaranteed; the presets show a cautious and a growth view.

    Last reviewed 27 September 2026

    Used in: Retirement Planner

  • Sustainable drawdown rate

    GuideStation assumption

    4% of the pot a year

    The share of a retirement pot that can be drawn each year as income without running it down, a widely used rule of thumb. It turns an income target into a capital target. Markets, fees and longevity all move the real figure.

    Last reviewed 27 September 2026

    Used in: Retirement Planner

Car

Our car tools mostly use estimates. Real finance and insurance prices depend on you and the provider.

  • Car affordability ratio

    Rough estimate

    finance repayment up to 35% of income left after expenses

    A budgeting rule of thumb for how much of your disposable income a car repayment should take. Insurance is added on top of the repayment.

    Last reviewed 27 September 2026

    Used in: Car affordability

  • Default vehicle finance rate

    Rough estimate

    13% (adjustable from 9% to 18%)

    A fixed starting rate for vehicle finance. It is not linked to prime, so it does not move when the SARB changes rates. Your actual rate depends on your credit profile and the lender.

    Last reviewed 27 September 2026

    Used in: Car finance, Car affordability, Total cost of ownership

  • Finance estimate on marketplace listings

    Rough estimate

    prime + 2 to prime + 4 percentage points (12.75%–14.75%)

    The quick estimate shown for a listing uses a band above prime rather than a single rate, because vehicle finance is priced by credit risk.

    Last reviewed 27 September 2026

    Used in: Car insurance estimate

  • Car insurance estimate

    Rough estimate

    0.4%–0.8% of the vehicle's value per month

    A rule-of-thumb band applied to the vehicle's price. It does not use your age, driving record, area or the vehicle's risk group, which drive real premiums. Get quotes for an actual price.

    Last reviewed 27 September 2026

    Used in: Car insurance estimate, Car affordability, Total cost of ownership

  • Vehicle depreciation

    Rough estimate

    15% of value per year

    A single average annual depreciation rate applied to every vehicle. Real depreciation varies widely by make, model, age and mileage.

    Last reviewed 27 September 2026

    Used in: Total cost of ownership

  • Fuel and maintenance starting values

    Rough estimate

    Starting monthly fuel and maintenance figures in the total-cost calculator. They are placeholders for you to replace with your own spend, not averages for your vehicle.

    Last reviewed 27 September 2026

    Used in: Total cost of ownership

Health

Medical scheme rules from the regulations, plus the rough estimates used for medical aid and pet cover.

  • Medical scheme late-joiner penalty bands

    Official data

    From age 35: up to 5% (1–4 years without cover), 25% (5–14 years), 50% (15–24 years) or 75% (25 or more years) of the relevant contribution

  • Medical aid contribution estimate

    Rough estimate

    Broad monthly price ranges for hospital, comprehensive and premium plan types, adjusted for income band and dependants. Not based on a scheme-by-scheme price dataset, and it does not model scheme-specific age or option pricing.

    Last reviewed 27 September 2026

    Used in: Medical aid estimator

  • Pet insurance premium estimate

    Rough estimate

    A base monthly premium adjusted by species, size, age and cover level. A rough guide to what cover might cost, not a quote from any insurer.

    Last reviewed 27 September 2026

    Used in: Pet cover

  • Vet bill scenarios

    Rough estimate

    Illustrative cost ranges for common emergencies (fractures, tick bite fever, poisoning, surgery, cancer, road accidents), to show how an excess and co-payment affect what you pay. Real bills vary by practice and region.

    Last reviewed 27 September 2026

    Used in: Pet cover

GuideStation's calculators are estimates for planning, not financial, tax or legal advice. If you spot a figure that looks out of date, please tell us through the contact page.