Question 1

How do I estimate my quarterly taxes?

Accepted Answer

Project your net self-employment income for the year (revenue minus expenses), estimate the total tax on it — self-employment tax or CPP plus federal and state/provincial income tax — then divide by four. This calculator does all of that: enter expected revenue and expenses and it shows the full-year estimate and the per-quarter payment with 2026 due dates.

Question 2

Do quarterly tax payments have to be equal?

Accepted Answer

No. In the US, the IRS default assumes four equal instalments, but if your income is uneven you can use the annualized income installment method (Form 2210 Schedule AI) to pay more in quarters when you earn more and less when you don't. In Canada, the CRA offers three options — its mailed reminder amounts, a prior-year calculation, or your own current-year estimate — and unequal payments are fine as long as you don't underpay.

Question 3

When are 2026 estimated taxes due?

Accepted Answer

US (IRS): April 15, June 15, and September 15, 2026, then January 15, 2027 for the final quarter. Canada (CRA): March 15, June 15, September 15, and December 15, 2026. If a date falls on a weekend or holiday, the deadline shifts to the next business day.

Question 4

What happens if I skip quarterly payments?

Accepted Answer

You don't go to jail — you pay interest. The IRS charges an underpayment penalty computed like interest on each missed instalment, and the CRA charges instalment interest (plus a further penalty if that interest exceeds $1,000). If your tax bill is small — under $1,000 owed in the US, or under $3,000 net owing in Canada — quarterly payments aren't required at all.

Question 5

What is the safe harbor rule?

Accepted Answer

In the US, you avoid all underpayment penalties if your four instalments total at least 100% of last year's tax (110% if your prior-year AGI was over $150,000) or 90% of this year's tax, whichever is smaller. Many freelancers simply pay last year's tax ÷ 4 each quarter and settle the difference in April.

Quarterly Tax Calculator

How do I estimate my quarterly taxes?

Do quarterly tax payments have to be equal?

When are 2026 estimated taxes due?

What happens if I skip quarterly payments?

What is the safe harbor rule?