How Much Could a Child’s TFSA Grow? See What’s Possible with this Growth Calculator

We made this calculator because we’ve been seeing a lot of videos on FinTok (and YouTube) talking about tax-free savings accounts (TFSAs) for kids in South Africa. A lot of these videos show wildly different results with some realistic, some not.

So instead of guessing, we built this tool to help you work it out for yourself. It shows you how powerful compound interest can be if you start early, follow the TFSA rules, and leave the money to grow for as long as possible.

This isn’t financial advice. It’s just a way to explore the numbers and maybe start thinking about long-term saving and creating generational wealth.

This TFSA Growth calculator helps you estimate how much money a child in South Africa could in the future have in a TFSA if you start saving for them now. Once you hit the lifetime contribution limit, the investment keeps growing for as long as you leave it, for example until your child turns 55

How the TFSA Growth Calculator Works

This calculator works in two parts. It helps you figure out:

  1. How long it will take to reach the R500,000 lifetime TFSA limit.
  2. How much that lump sum could grow to over time if you leave it alone.

Part 1: Contribution Phase

This part looks at how long it will take to reach the R500,000 lifetime contribution limit for a TFSA, based on your regular contributions. For example, if you contribute R3,000 per month, you’ll hit the limit in just under 14 years.

You can choose to:

  • Contribute monthly (up to R3,000/month).
  • Or contribute annually (up to R36,000/year).

You also set:

  • The child’s starting age (e.g. birth, or age 5).
  • An interest rate.
  • Whether the growth is compounded monthly or annually.

We assume you stop contributing as soon as you hit R500,000, which is the current SARS lifetime cap.

The result is the total lump sum you’ll have once you’ve stopped contributing. This includes both your contributions and the interest earned during those years.

Part 2: Growth Phase

Now that you’ve reached the R500,000 cap, you can’t add any more money but you can leave the lump sum to grow.

Here you’ll:

  • Choose the age you’ll leave the investment until (e.g. age 45, 55, 65).
  • Set an interest rate (maybe lower, depending on the market or fund).

The calculator shows you what that lump sum could grow into if untouched. This is where compound interest does the heavy lifting.

TFSA Rules and Assumptions

  • Max yearly contribution: R36,000.
  • Max lifetime contribution: R500,000.
  • Interest is compounded monthly or annually, based on your choice.
  • No fees or withdrawals are included (this is a simplified estimate).
  • Contributions stop automatically once the R500,000 limit is reached.
  • You can start contributing at any age.

Part 1: Contributions Phase

Results (Part 1):

Total Years of Contribution: 0 years

Child’s Age When Contributions Stop: 0 years

Total Contributions Made: R 0.00

Interest Earned (Contributions): R 0.00

Lumpsum at End of Contribution Phase: R 0.00

Part 2: Growth Phase

Results (Part 2):

Years of Growth (Post-Contribution): 0 years

Total Future Value at Age 0: R 0.00

Interest Earned (Growth): R 0.00

What variables can you change?

You can adjust:

  • The child’s starting age
  • Monthly contribution amount (capped at R3,000 to simplify calculations)
  • The interest rate (to reflect different investment options)
  • Monthly or annual compounding
  • The age you’ll leave the investment until (e.g. age 45, 55, etc.)

Why this is useful

This calculator helps you test different “what if” scenarios using SARS rules and reasonable interest rates. It helps you understand the effect of:

  • Starting early
  • Staying consistent
  • Leaving the money untouched for as long as possible

It’s a way to get a realistic idea of what a TFSA for your child could become without relying on TikTok hype. Do not take this as financial advice. The calculator is useful for planning and seeing the power of compound interest.

The exact calculation for Current Future Value in the first part of the calculation can be tricky when mixing annual/monthly contributions with monthly compounding and hitting a lifetime limit. The current loop approximates this by compounding the existing sum monthly and adding the annual/monthly contribution within the year. For highly precise financial calculations, specialised financial libraries might be used, but this should be sufficient for our purposes of a web calculator’s estimation. The crucial part is accurately tracking ‘Total Contributions Made’ against the Lifetime Limit.

FAQs

According to the current regulations, it takes 13 years and 11 months to reach the lifetime TFSA contribution limit of R500,000 if you’re contributing the maximum allowed amount of R3,000 per month every month.

If you contribute R3,000 a month for 13 years and 11 months (starting from age 0), and the investment earns 10% interest compounded monthly, the lump sum at the end of the contribution period could be just over R1 million. If you leave that to grow untouched until age 65, it could grow to more than R170 million, depending on the interest rate.

As of current SARS rules, the maximum you can contribute to a TFSA is R36,000 per year and R500,000 over your lifetime. Any extra contributions above these limits are taxed at 40%.

Yes. Parents can open a TFSA in their child’s name. Contributions will count toward the child’s lifetime limit, not the parent’s. It’s a popular way to build long-term wealth for your child, especially if started early.

Many online examples use different interest rates, ignore SARS limits, or assume unrealistic timeframes. This calculator uses actual TFSA limits and lets you tweak real variables like contribution size, age, and interest rate so you get a more accurate and personalised estimate.

Sherissa R

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