Adjusted Cost Base: How To Calculate Your ACB

Calculating your adjusted cost base (ACB) is necessary to determine the true cost of your investments for capital gains and losses. If you want a good idea of what kind of returns you are really getting, you need to figure out your adjusted cost base. And, perhaps more importantly, the CRA requires this calculation to be used for income taxes in relation to capital gains and losses. If you want to make sure you stay in the good books with the CRA, you need to make sure you understand how to perform this calculation.

Calculating Your Adjusted Cost Base

The adjusted cost base is calculated by of adding in the cost you paid to purchase all of your investments into a certain stock or mutual fund. When you consider your ACB, you also need to make sure that you are including any reinvested distributions, as well as any commissions or fees incurred to purchase that stock or mutual fund. You want to make sure that all of your costs are represented. Your total cost is then divided by the total number of shares or units you own.

For example, say you buy 500 shares in a company for $15 each. Later, the stock price falls so you decide to  buy 200 more shares in that company at $12 each. You also have to pay a commission of $20 for each transaction.

500 x $15 = $7,500
200 x $12 = $2,400
2 x $20 =$40

$7,500 + $2,400 + $40 = $9,940

The total cost of your investment is $9,940. Now you divide that amount by the 700 shares that you own. The result is an ACB of $14.20 per share

In this example, your adjusted cost base is $14.20. Capital gains or capital losses are then simply calculated as the difference between the ACB and the sale price minus commissions.

Continuing with the example above, let’s see what would happen if you were to sell 100 shares for $15:

Sell 100 x $15 ($1,500)  – $20 for the commission = $1,480
ACB 100 x $14.20 = $1,420

As you can see, you have a capital gain of $60. That is the amount on which the CRA will tax you.

But what if you end up selling for less than the ACB of $14.20 a share? Below, you can see the result if you were to sell 100 shares for $13:

Sell 100 x $13 ($1,300)  – $20 for the commission = $1,280
ACB 100 x $14.20 = $1,420

Now you have a capital loss of $140. You can use that loss to offset capital gains you might have, lowering your investment income for tax purposes.

Reduce Your Fees to Improve Your ACB

Lowering the cost of commissions is a good way to improve your adjusted cost base. You can use a discount online broker to help you save money on transactions fees. I use Questrade in part because of the low $4.95 transaction fee. (It’s also worth noting that you can get $50 to go toward paying commissions when using the CanadianFinance promo code at Questrade.)

Calculating your adjusted cost base is not only mandated by the CRA, but it’s also useful for tracking your investments. When you know the adjusted cost base per share, it allows you to make far more meaningful comparisons to the current prices in the market.

Calculating your adjusted cost base (ACB) is necessary to determine the true cost of your investments for capital gains and losses.

Written by Tom Drake

Tom Drake is the owner and head writer of Canadian Finance Blog. While you’re here, consider signing up for the RSS feed or email subscription. Both deliver the latest articles directly to you! You can also follow me on Twitter for all the latest posts or to send me any comments or questions!

20 Responses to Adjusted Cost Base: How To Calculate Your ACB

    • There is a site that provides ACB calculations that take into account ROC which reduce the ACB as well as Phantom distributions which add to the ACB. Take a look at . They specialize in calculating ACBs for ETFs, REITs, Closed-end Funds, and Income Trusts.

  1. When a stock pays a dividend (part of it being ROC (Rtn of Cap) and part of it being Capital Gain), does the Capital Gain also affect our Adjusted Cost Base? Assuming so (because we are paying capital gains tax on that portion), should we add the capital gain to our original cost?

    • Yes, if you received a T3 or T5 which shows a internal capital gain paid in an ETF or mutual fund, then you should ensure that your brokerage added the capital gain to your per share cost base.

      basic calc:
      Initial cost per share – ROC + Capital Gains = New ACB

  2. When a stock is transferred out of an RRSP What value is to be used for the ACB? The original purchase price or the transfer out value?

    • Nimrod,
      Do you mean that a stock was transferred out of an RRSP and then later sold? I’m not positive, but I would think it would be the value when transferred since it’s basically considered a sale and purchase at that time?

  3. Apr 16/11
    Using your ACB example above, what would be the new ACB per share on the 500 remaining shares (500+200-100-100)? And how does one make this calculation?

  4. Alot of examples of ACB’s online show you step by step how to get to an adjusted cost base number, but none talk about whether you are supposed to be adding the number of all shares including the current year or just up to the tax year you are trying to calculate for?
    I’m likely guessing that you don’t include any current year shares in total since they would skew capital gain/loss.
    What about reverse splits?? How do you handle these?

  5. Hello Tom,
    Can you provide an example of calculating ACB with mutual funds? As they are priced on a daily basis, so one never knows how many units they will acquire from a purchase until the following business day. I find the above example leaning stocks and I am not familiar with stocks to begin with. Maybe it can show purchases from different dates?…
    Can I also assume that the stock example above is displaying two purchases made on the same day?
    Thanks Tom, RJP

  6. Are there any computer applications that provide for inputting data relative to mutual fund monthly dividends received and return on capital to compute the calculations to arrive at the adjusted cost basis when sell ing these mutual funds.

  7. First, your numbers don’t add up. Your example shows the correct $ figure BUT not the correct addition of number of shares. (702) Average cost is then 14.16 but confidence in analysis is undermined.
    Second no site I can find mentions the impact of ‘reinvested dividends’ (used to purchase additional shares) on adjusted cost basis. Since tax has been paid on dividends received over the years real capital gains should be only the change in the initial investment amount – with all reinvested dividends subtracted.
    Your thoughts?

    • Sorry. the missing $40 is transaction costs.My first point is in error. Second question still remains: reinvested dividends over the years.DRIPS or dividend reinvestment plans.

  8. On the topic of re-investing dividends: it’s really no different than investing in additional shares using funds that were not initially dividends. Your ACB is calculated by dividing the total number of shares now held by the total cost of acquiring those shares – including commissions [though there usually arent’ commission costs fro DRIP’s]. The acquiring cost is simply increased by the dividends used to buy the additional shares.

  9. I am selling a home I lived in for 9 years and rented for 10 years after that. How do I calculate the ACB for the home when calculating capital gains.

  10. What if I own, for example,
    1000 shares Enbridge purchased through TD Waterhouse
    1000 shares Enbridge purchased through HSBC

    and I’m selling ONLY the shares purchased at TD Waterhouse.

    Do I still calculate the average cost including the shares purchased through HSBC, even though I’m not selling them?

  11. hypothetically speaking, how would it be possible to increase my ACB of common shares from $100 to $400,000 over the course of 5 years?

  12. If you hold shares in a REIT on the declaration date and then sell ALL the units before the distribution date, are all of the funds received on that last distribution date a Capital Gain regardless of how the T3 broke out the distributions for the year, i.e. ROC, CG, Foreign Non-business income or is the status of the distribution set at the declaration date and then treated per the T3? Is it the same for receiving an eligible dividend after having sold all the shares?

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