Ontario HST Calculator Guide: 13% Tax Formula and Examples

Ontario HST Rate at a Glance

Ontario uses 13% HST for most taxable goods and services.

• Add tax formula: Subtotal × 1.13
• Remove tax formula: Total ÷ 1.13
• HST portion: Total - (Total ÷ 1.13)

If you invoice customers in Ontario, this is the default rate unless a specific exemption applies.

Quick Examples

Example 1: Add HST

• Subtotal: $250.00
• HST (13%): $32.50
• Total: $282.50

Example 2: Remove HST

• Tax-in total: $565.00
• Pre-tax: $565.00 ÷ 1.13 = $500.00
• HST included: $65.00

Common Ontario Scenarios

1. Retail invoices: Use 13% on most taxable items.
2. Service businesses: Apply 13% to eligible professional services.
3. Interprovincial sales: Use place-of-supply rules, not your office location.

For detailed place-of-supply context, see the E-commerce Tax Guide for Canada.

Related Guides

• Current Canadian Tax Rates by Province (2026)
• Reverse GST/HST Calculation Guide
• Complete Guide to GST & HST in Canada

Calculate Ontario HST instantly with the Canada GST/HST calculator →

FAQ: Ontario HST

Is Ontario HST always 13%?

For most taxable supplies, yes. Special exemptions and zero-rated supplies can change how tax appears.

How do I back-calculate HST from a receipt?

Divide the tax-in total by 1.13 to get pre-tax, then subtract from the total.