From HT to TTC
HT amount
+
Tax amount
=
TTC amount
Tax amount = HT amount × Tax rate
TTC amount = HT amount + Tax amount
Use this method when your starting amount is before tax and you want to add tax on top.
Gombo Tools
HT/TTC Calculator
Use this free HT/TTC calculator to convert between amounts excluding tax and amounts including tax. Enter an amount, choose the calculation mode, and apply the tax rate you need. It is useful for quotes, invoices, price checks, and tax-inclusive pricing.
Result overview
Amount excluding tax
100,000
Tax amount
18,000
Total including tax
118,000
How to calculate HT and TTC
HT means the amount before tax. TTC means the amount including tax. To move from HT to TTC, add tax. To move from TTC to HT, extract the tax from the total.
From TTC to HT
TTC amount
÷
1 + Tax rate
=
HT amount
HT amount = TTC amount ÷ (1 + Tax rate)
Tax amount = TTC amount − HT amount
Use this method when your starting amount already includes tax and you need to extract the before-tax amount.
Use the tax rate as a decimal in formulas. Example: 18% = 0.18.
How to use this calculator
- Enter the amount
- Enter the tax rate
- Choose whether you want to calculate from HT to TTC or from TTC to HT
- Read the HT amount, tax amount, and TTC amount
Examples
Example 1: HT to TTC
- HT amount
- 100,000
- Tax rate
- 18%
- Tax amount
- 18,000
- TTC amount
- 118,000
Example 2: TTC to HT
- TTC amount
- 118,000
- Tax rate
- 18%
- HT amount
- 100,000
- Tax amount
- 18,000
Tips
Confirm whether your starting price is HT or TTC.
Check the tax rate that applies in your country or market.
Use consistent rounding rules for invoices and accounting.
Keep quotes and invoices organized to avoid manual tax mistakes.
Need to manage HT, TTC, and invoices automatically?
Gombo helps you create invoices, manage customers, track payments, and monitor business operations from one connected platform.