Ten years is long enough for compounding to matter — and short enough that contributions do most of the heavy lifting.
Run this in Money GrowthIn the first decade, your contributions are usually the biggest driver. Compounding still helps, but it really accelerates when your balance becomes larger.
| Return rate | Final balance | Total contributed |
|---|---|---|
| 5% (conservative) | ~$67,000 | $52,000 |
| 7% (mid) | ~$75,000 | $52,000 |
| 10% (optimistic) | ~$89,000 | $52,000 |
Investing $100 a week for 10 years means contributing $52,000 of your own money — and at a 7% return, compounding adds around $23,000 on top, growing your balance to roughly $75,000. Ten years is a solid start, with compounding adding nearly half as much again to your contributions. For many Australians this is a realistic first decade of serious investing — building a foundation that grows much faster if you keep going into a second decade.
For Australians, $100 a week is a realistic amount to invest outside of superannuation — roughly what you might direct into a low-cost index ETF like VAS or VGS each week. At a 7% average annual return (broadly in line with long-run ASX and global index performance), your $52,000 in contributions grows to around $75,000 over 10 years. That's a meaningful buffer on top of whatever super is accumulating in the background. If you're using a platform like Sharesight to track your portfolio, you'll be able to see exactly how your actual returns compare to these projections over time.
Ten years is a solid start, but the real power of compounding kicks in when you extend the timeline. Here's how $100 a week compares across different time horizons at a 7% return:
| Time period | Total contributed | Final balance (7%) | Growth from compounding |
|---|---|---|---|
| 10 years | $52,000 | ~$75,000 | ~$23,000 |
| 20 years | $104,000 | ~$274,000 | ~$170,000 |
| 30 years | $156,000 | ~$756,000 | ~$600,000 |
Notice how compounding growth jumps from $23,000 at 10 years to $600,000 at 30 years — even though contributions only tripled. That's the compounding effect accelerating as your balance grows larger.
Convert $100/week to monthly: about $433/month ($100 × 52 ÷ 12). Then test 5%, 7% and 10% return assumptions.
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It’s a strong habit. Over 10 years you contribute meaningfully, and compounding adds extra growth.
They may assume different compounding frequency, contribution timing, or rounding.
Use $0 if you’re starting from scratch, or enter your current balance if you already have investments.
This calculator uses monthly contribution. Converting weekly → monthly is a good approximation for planning.
Real markets move up and down. The rate is an average assumption to help you compare scenarios.
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