Formula to Calculate Hst From Total Ontario

In Ontario, the Harmonized Sales Tax (HST) is a combined sales tax and Goods and Services Tax (GST) rate. This guide explains how to calculate the HST amount from a total price in Ontario, including the formula, step-by-step instructions, and a working calculator.

How to Calculate HST from a Total in Ontario

When you see a total price in Ontario that includes HST, you can calculate the HST amount using the following steps:

Identify the total amount including HST.
Determine the HST rate (currently 13% in Ontario).
Use the formula to calculate the HST amount.
Subtract the HST amount from the total to find the pre-tax amount.

This process helps you understand how much of the total price is tax and how much is the actual product or service cost.

The Formula

The formula to calculate the HST amount from a total in Ontario is:

HST Amount = Total Amount × (HST Rate / (1 + HST Rate))

Where:

HST Amount is the tax portion of the total price.
Total Amount is the price including HST.
HST Rate is the current tax rate (13% in Ontario).

This formula accounts for the fact that the total amount already includes the HST, so we need to reverse-calculate the tax portion.

Worked Example

Let's calculate the HST for a total amount of $100 in Ontario:

Total Amount = $100
HST Rate = 13% or 0.13
HST Amount = $100 × (0.13 / (1 + 0.13)) = $100 × 0.1194 ≈ $11.94

The HST amount is approximately $11.94, and the pre-tax amount would be $100 - $11.94 = $88.06.

Frequently Asked Questions

What is the current HST rate in Ontario?: The current HST rate in Ontario is 13%. This combines the provincial sales tax and the federal GST.
How do I calculate the pre-tax amount from a total including HST?: You can use the formula: Pre-tax Amount = Total Amount / (1 + HST Rate). For a $100 total, this would be $100 / 1.13 ≈ $88.06.
Is the HST rate the same for all provinces?: No, the HST rate varies by province. Ontario has a 13% HST rate, while other provinces have different rates or use a separate PST and GST.
Can I use this calculator for other provinces?: This calculator is specifically for Ontario's 13% HST rate. For other provinces, you would need to use their specific tax rates.
What if the total amount doesn't include HST?: If the total amount doesn't include HST, you would simply multiply the amount by the HST rate to find the tax amount.