Investment frequency calculator: ETF & shares
Determine how often you should invest in shares or ETFs by balancing brokerage fees against opportunity cost. This calculator helps you find the best investment frequency to maximise returns while minimising trading costs.
Why Use This Calculator
Finding the best investment frequency balances two key factors: brokerage fees and opportunity cost. Investing too frequently means paying more in brokerage fees, while investing too infrequently means missing out on potential returns by keeping money in low-interest savings accounts.
- Calculate the best investment frequency for your situation
- Balance brokerage fees against opportunity cost
- Maximise returns while minimising trading costs
- Make informed decisions about when to invest
Enter Your Investment Details
Enter your income frequency, savings amount, and investment parameters to find the best investment frequency for your situation.
The interest rate you earn on your savings account before investing.
Your expected annual return from shares or ETFs. Typical returns range from 5-10% annually.
The brokerage fee you pay per trade. Typical Aussie brokers charge $5-$20 per trade.
The time period over which to calculate the best investment frequency.
Best Investment Frequency
Based on your inputs, investing every quarterly provides the best balance between brokerage fees and opportunity cost.
Portfolio Growth Over Time
This chart shows how your portfolio value grows over 5 years for different investment frequencies. It demonstrates the long-term impact of choosing the best frequency.
Frequency Comparison(over 5 years)
| Frequency | Trades/Year | Total Brokerage Fees(over 5 years) | Total Opportunity Cost(over 5 years) | Net Benefit(over 5 years) |
|---|---|---|---|---|
| Daily(Best for your broker) | 365 | $17,337.50 | $1.85 | $-17,339.35 |
| Weekly | 52 | $2,470.00 | $12.98 | $-2,482.98 |
| Fortnightly | 26 | $1,235.00 | $25.96 | $-1,260.96 |
| Monthly | 12 | $570.00 | $56.25 | $-626.25 |
| Quarterly(best for you) | 4 | $190.00 | $168.75 | $-358.75 |
| Twice-yearly | 2 | $95.00 | $337.50 | $-432.50 |
| Annually | 1 | $47.50 | $675.00 | $-722.50 |
Cost Breakdown
Compare brokerage fees and opportunity cost across different investment frequencies.
Net Benefit Comparison
The net benefit shows the total cost (brokerage fees + opportunity cost) for each frequency. Higher values (less negative) are better.
Find the Best ETFs for Your Investment Strategy
Browse our comprehensive list of Australian ETFs to find the best options for your portfolio.
Browse All ETFs →Frequently Asked Questions
What's the purpose of this calculator?
Fair dinkum, this calculator helps you figure out the sweet spot for investing in shares or ETFs by balancing two key factors: brokerage fees and opportunity cost. Investing too often means you're throwing money at your broker like confetti, while investing too rarely means your hard-earned cash is sitting in a savings account earning peanuts instead of working for you in the market.
What is the mathematics behind this?
Righto, the calculator compares different investment frequencies by crunching the numbers on:
- Brokerage Fees: How many times you trade per year multiplied by what your broker charges (because they're not running a charity, mate)
- Opportunity Cost: The gap between what you could earn investing versus what you're getting in your savings account, applied to the average amount sitting in savings before you invest
- Net Benefit: The total cost (brokerage fees + opportunity cost). The lower the total, the better the frequency. Simple as that.
The best frequency is the one that keeps these two costs as low as possible. For the full mathematical breakdown (if you're into that sort of thing), check out this Money StackExchange discussion.
What if I'm investing in multiple shares/ETFs?
If you're spreading your bets across multiple shares or ETFs (smart move, by the way), you can run this calculator for each investment separately, or just use your total savings amount. Just remember: every time you buy a different security, your broker gets another fee. So if you're building a diversified portfolio, those fees can add up faster than a bar tab on a Friday night, which might change what the best frequency looks like.
What should I invest in? Can you give me investment advice?
Look, this calculator tells you when to invest, not what to invest in. We're not financial advisors (and even if we were, we couldn't give you personalised advice over the internet). Before you start throwing your money around, have a yarn with a qualified financial advisor who can look at your specific situation. In the meantime, feel free to browse our ETF listings to do your own research and see what's out there.
Disclaimer: This calculator provides estimates based on the inputs provided. Actual investment returns and brokerage fees may vary. Past performance does not guarantee future results. This is not financial advice. Please consult with a qualified financial advisor before making investment decisions.