Each year brings a myriad of changes to the taxes that Canadians must pay.

But changes to the way taxes are calculated on capital gains could make filling out this year's tax return an especially complicated effort this time around.

So what makes this year different?

At the start of 2000, the capital gains inclusion rate that portion of a gain on the sale of securities or property that is subject to tax stood at 75 per cent. That means three-quarters of any capital gains would be taxable. The remaining 25 per cent is not.

But when Finance Minister Paul Martin delivered his budget last February, he lowered the rate to two-thirds. And he didn't stop there.

In October, Martin got to his feet in the House of Commons and lowered the rate again, this time to 50 per cent.

The cuts will leave more money from capital gains in the pockets of Canadians. But they also make for some complicated tax calculations because there are three different inclusion rates covering three periods of this year.

Here's how things work:

• Capital gains triggered in Period 1 (Jan. 1 to Feb. 27) carry an inclusion rate of 75 per cent
• Capital gains triggered in Period 2 (between Feb. 28 and October 17 ) carry an inclusion rate of 66 2/3 per cent
• Capital gains triggered in Period 3 (after October 17) carry an inclusion rate 50 per cent
Got that?

Before you start pounding the calculator keys, you'll need to know three things: what the investment cost to buy, the date when it was sold and the sale price. Don't forget to adjust for commissions on purchases and sales when figuring out net capital gains or losses. For example, commissions paid when buying a stock are added to the purchase cost. Conversely, commissions paid when a stock is sold are deducted from the proceeds.

Once you know your capital gain or loss for each of the three periods in question, you can calculate your inclusion rate and taxable capital gain for the year. This is where things can get complicated, especially if you've got capital gains and losses in each period.

To make things easier, several free calculators are available on the Internet. They'll help you calculate your inclusion rate and capital gains subject to tax for the entire year.

Here are a couple:

The Canada Customs and Revenue Agency has an in-depth site on capital gains and inclusion rates. The government site goes through examples of how to manually calculate inclusion rates and capital gains depending on when the gains were realized.

You can reach this site at:

Because of the changes to the inclusion rates for 2000, the capital gains tax form is four pages long. So even if you're normally a do-it-yourselfer, this year's complications may prompt you to consider tax preparation software. As an added bonus, many of the software packages are cheaper to download from the Internet than they are to buy in stores.

Popular online tax software packages include:

The deadline for filing your 2000 tax return is Monday April 30 at midnight local time.