South Dakota sales tax calculator
The South Dakota state sales tax rate is 4.2%. City, county and special-district taxes stack on top, so set the combined rate if you know it.
%
Total with tax
104.20
- Tax added
- 4.20
- Total for the quantity
- 104.20
- Price before tax, working backwards
- 102.93
- Tax inside a tax-inclusive price
- 4.32
- Tax as a share of the total
- 4.0307 %
- Multiply the net price by this
- 1.042 000
Show the working
- Price before tax = 100
- Sales tax rate = 4.2
- Or a price that already includes tax = 107.25
- Quantity = 1
- Tax added = 100 * 4.2 / 100 = 4.2
- Total with tax = 100 + 4.2 = 104.2
- Total for the quantity = 104.2 * 1 = 104.2
- Price before tax, working backwards = 107.25 / (1 + 4.2/100) = 102.927
- Tax inside a tax-inclusive price = 107.25 - 102.927 = 4.322 94
- Tax as a share of the total = 104.2 > 0 ? 4.2 / 104.2 * 100 : 0 = 4.030 71
- Multiply the net price by this = 1 + 4.2/100 = 1.042
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- tax = price x rate
- total = price x (1 + rate)
- to remove tax: net = gross / (1 + rate), never gross x (1 - rate)
Removing a tax is division, not subtraction. Taking 7.25% off a tax-inclusive price undercharges you every time.
Rates change and local additions vary by address. Treat the prefilled rate as a starting point and check the current combined rate for the exact jurisdiction.
Frequently asked
What is the sales tax rate in South Dakota?
The state base rate is 4.2%, before any city, county or district additions.
How do I work out the price before tax?
Divide the tax-inclusive price by 1 plus the rate. At 4.2% that means dividing by 1.0420.
Where the numbers come from
- State base rates as published by state revenue departments; local additions are not included.