Small Business Tax Calculator 2024-2025: Easily Estimate Your Taxes & Maximize Savings

Understanding your tax obligations as a small business owner in Canada is crucial for financial planning and compliance.
With the right knowledge, you can optimize your tax strategy and potentially save thousands of dollars for your business. Proper tax planning not only helps you meet your legal obligations but also contributes to the long-term financial health of your enterprise.
Let’s take a quick look at how small business tax rates apply in Ontario before calculating your tax.
Understanding Small Business Tax Rates in Ontario
In Canada, small businesses benefit from the “small business deduction (SBD),” which offers a lower tax rate on the first $500,000 active business income. A reliable small business tax calculator can help you understand these rates. Here’s how it works:
- For profits up to $500,000: The federal small business tax rate is 9%, and provincial rates vary, creating a combined rate of approximately 12.2% (average across provinces)
- For profits over $500,000: The general corporate tax rate applies, which is about 26.5% (combined federal and provincial rates)

This two-tier system is designed to help small businesses grow by allowing them to keep more of their early profits.
Ontario Small Business Tax Calculator
One Accounting has developed a Small Business Tax Calculator to help small businesses quickly estimate their tax liabilities. This user-friendly tool simplifies tax calculations by automatically applying the correct tax rate based on business profits. With this calculator, small business owners can better plan their finances and ensure compliance with Ontario’s tax regulations.
Small Business Tax Calculator
Understanding Small Business Tax Rates in Canada
- Determine your business’s taxable income (revenue minus eligible expenses)
- Multiply your taxable income by 12.2%
- The resulting amount is your approximate tax obligation
For Businesses with Profits Below $500,000
Example:
A small consulting business in Canada earns $250,000 in taxable income for the year.
Tax calculation: $250,000 × 12.2% = $30,500
This business would pay approximately $30,500 in combined federal and provincial corporate taxes.
For Businesses with Profits Over $500,000
If your business profits exceed the $500,000 threshold, the calculation involves two steps. Many entrepreneurs rely on a small business tax calculator to handle these more complex scenarios:
- For the first $500,000: Multiply by 12.2%
- For any amount over $500,000: Multiply by 26.5%
- Add these two amounts together for your total tax obligation
Example:
A growing manufacturing business earns $750,000 in taxable income.
Tax on first $500,000: $500,000 × 12.2% = $61,000
Tax on remaining $250,000: $250,000 × 26.5% = $66,250
Total tax: $61,000 + $66,250 = $127,250
Jumping into a Reddit thread, here’s what users had to say about estimating small business taxes:

To better understand the overall tax burden, let’s examine the Combined Corporate Tax Rates in Canada.
Combined Corporate Tax Rates in Canada

How Combined Tax Rates Are Calculated
The combined tax rate is the sum of the federal and provincial corporate tax rates. For example:
- Small Business Rate in Ontario: 3.2% (provincial) + 9% (federal) = 12.2%
- General Corporate Rate in Ontario: 11.5% (provincial) + 15% (federal) = 26.5%
Example: ABC Company (Ontario)
- Taxable income: $600,000
- All income from ordinary business activities in Canada
Step 1: Calculate taxes on the first $500,000 (eligible for SBD)
- $500,000 × 12.2% (Small Business Tax Rate) = $61,000
Step 2: Calculate taxes on the remaining $100,000
- $100,000 × 26.5% (General Corporate Tax Rate) = $26,500
Step 3: Determine the total corporate taxes payable
- $61,000 + $26,500 = $87,500
Maximizing tax efficiency is crucial for businesses looking to reduce their overall tax burden. One effective way to achieve this is by taking advantage of various deductions. Below are some Key Deductions That Can Lower Your Taxable Income.
Key Deductions That Can Lower Your Taxable Income
Before calculating your taxes, make sure you’re claiming all eligible deductions to reduce your taxable income. A comprehensive small business tax calculator should factor in these deductions:
- Business operating expenses: Rent, utilities, supplies, and marketing costs
- Salary and wages: Payments to employees, including yourself if you’re incorporated
- Capital cost allowance (CCA): Depreciation of business assets like equipment and vehicles
- Home office expenses: A portion of home-related costs if you work from home
- Vehicle expenses: Business-related automobile costs
- Professional fees: Accounting, legal, and consulting services
Conclusion
Understanding the 12.2% tax rate for profits under $500,000 and the 26.5% rate for profits over that threshold is fundamental for Canadian small business tax planning. By keeping good records, maximizing deductions, and considering professional advice when needed, you can ensure your business remains tax-compliant while minimizing your tax burden.
Contact One Accounting for more detailed calculation that takes into account your specific business structure, provincial location, and potential deductions to ensure you’re neither overpaying nor risking non-compliance.