In most countries, B2C prices are tax-included. To do that in Odoo, check Included in Price for your sales taxes in .
This way the price set on the product form includes the tax. As an example, let's say you have a product with a sales tax of 10%. The sales price on the product form is $100.
Si la taxe n'est pas comprise dans le prix
Prix hors taxe : 100 €
Taxes : 10 €
Total à payer : 110 €
Si la taxe est comprise dans le prix
Prix hors taxe : 90.91 €
Taxes : 9.09 €
Total à payer : 100 €
You can rely on following documentation if you need both tax-included (B2C) and tax-excluded prices (B2B): Comment gérer les prix pour le B2B (HT) et pour le B2C (TTC) ?.
Show tax-included prices in eCommerce catalog
By default prices displayed in your eCommerce catalog are tax-excluded. To display it in tax-included, check Show line subtotals with taxes included (B2C) in (Tax Display).