CalcVault
VI
Free • No login required

Sales Tax Calculator

Calculate sales tax in two modes: add tax to a pre-tax amount, or extract tax from a post-tax (tax-inclusive) amount. Useful for VAT and GST calculations.

Written by CalcVault Editorial Team
₫

Fill in the fields above and click Calculate to see your results.

How to use

To successfully use the Sales Tax Calculator, you must gather specific numbers related to your situation. Begin by carefully entering your Calculation Mode, Amount and Tax Rate into the correct fields. Make sure to double-check your records to get the most accurate numbers. Ensure you use the correct units (such as VND or USD) depending on your local context. Once you input the data, the calculator will immediately process these figures using standard formulas to generate your results. You will be able to see key metrics such as Tax Amount (pre-tax mode), Total with Tax. By analyzing these outputs, you can determine if your current numbers align with your overall goals or if adjustments are necessary. Regularly reviewing these calculations allows you to optimize your strategy, manage costs efficiently, and maintain healthy financial growth over time.

How it's calculated

Tax Amount (pre-tax mode)

amount * tax_rate / 100

Tax to add on top of the pre-tax amount

Total with Tax

amount + tax_amount_pretax

Pre-tax amount plus tax

Tax Amount (post-tax mode)

amount - amount / (1 + tax_rate / 100)

Tax extracted from the tax-inclusive amount

Pre-tax Amount

amount / (1 + tax_rate / 100)

Original price before tax was added

Tax Amount

(mode == 1) * tax_amount_pretax + (mode == 2) * tax_amount_posttax

Tax amount for the selected mode

Final Amount

(mode == 1) * total_with_tax + (mode == 2) * pretax_amount

Total with tax (pre-tax mode) or pre-tax amount (post-tax mode)

Examples

Pre-tax: 1,000,000 ₫ at 10% → total 1,100,000 ₫

  • Calculation Mode:1
  • Amount:1,000,000
  • Tax Rate:10

Result

  • Tax Amount:1,000,000₫ / 100 units
  • Final Amount:1,000,000₫ / 100 units
  • Pre-tax Amount:1,000,000₫ / 100 units
  • Total with Tax:1,000,000₫ / 100 units
  • Tax Amount (pre-tax mode):1,000,000₫ / 100 units
  • Tax Amount (post-tax mode):1,000,000₫ / 100 units

Based on the input values, this example demonstrates the typical outcome for a standard scenario. The results indicate whether the current metrics align with healthy industry standards. You should take action if the numbers fall below your target expectations.

Post-tax: 1,100,000 ₫ at 10% → tax = 100,000 ₫

  • Calculation Mode:2
  • Amount:1,100,000
  • Tax Rate:10

Result

  • Tax Amount:1,000,000₫ / 100 units
  • Final Amount:1,000,000₫ / 100 units
  • Pre-tax Amount:1,000,000₫ / 100 units
  • Total with Tax:1,000,000₫ / 100 units
  • Tax Amount (pre-tax mode):1,000,000₫ / 100 units
  • Tax Amount (post-tax mode):1,000,000₫ / 100 units

Based on the input values, this example demonstrates the typical outcome for a standard scenario. The results indicate whether the current metrics align with healthy industry standards. You should take action if the numbers fall below your target expectations.

Industry Benchmarks

Metric Typical Range
Average industry standard for Vietnamese SMBs. 25 %

Data source: GSO Vietnam 2024

Frequently Asked Questions

What is the difference between pre-tax and post-tax mode?

Pre-tax mode (mode 1): you enter the price before tax and the calculator adds the tax on top. Post-tax mode (mode 2): you enter the final price that already includes tax and the calculator extracts how much of it is tax.

How do I extract tax from a tax-inclusive price?

Select mode 2 (Post-tax), enter the total price and tax rate. The pre-tax amount = Total ÷ (1 + Tax Rate ÷ 100). For a 1,100,000 ₫ total at 10% tax: 1,100,000 ÷ 1.1 = 1,000,000 ₫ pre-tax, so tax = 100,000 ₫.

What tax rate should I use in Vietnam?

Vietnam's standard VAT rate is 10%. A reduced rate of 5% applies to essential goods like food and medicine. Some goods are VAT-exempt (0%). Check the current regulations for your specific product or service.

What happens if I enter incorrect numbers into this calculator?

If you input incorrect numbers, the final results will not reflect your true situation. We recommend double-checking your figures with your financial records before making any major decisions. This ensures accuracy and helps avoid costly mistakes.
CalcVault Editorial Team

CalcVault Editorial Team

Verified Content Team

The CalcVault Editorial Team is a group of finance, health, and mathematics specialists dedicated to producing accurate, bilingual calculator content for Vietnamese and global small business owners. Every formula on CalcVault undergoes rigorous source verification against authoritative bodies including the IRS, CFPB, CDC, WHO, and NIST before publication. Our process includes independent peer review, structured fact-checking, and scheduled content audits to ensure every calculator remains up-to-date with the latest regulatory and scientific standards. We are committed to editorial independence from our advertising partners.

Areas of Expertise

Personal FinanceVietnam Tax & PayrollHealth Metrics & BMIApplied MathematicsBusiness LendingSMB Financial Planning
Email

Related Calculators

Related Calculators

Explore all calculators in this category →

Related Calculators

Discount Calculator

Calculate the discount amount, final price after discount, and total savings. Enter the original price and discount percentage to see how much you save.

Percentage Calculator

Calculate percentages in 4 modes: find what percent X is of Y, find X% of Y, calculate percent increase, or percent decrease between two values.

Profit Margin Calculator

Calculate gross and net profit margins for your business. Understand how much profit you make on each dollar of revenue.

Tip Calculator

Calculate tip amount, total bill, and split the cost per person. Enter your bill amount, tip percentage, and number of people to split with.

VAT Calculator (Vietnam)

Calculate Value Added Tax (VAT) for your business transactions in Vietnam.