Boulder ordinary retail uses 9.195%, not 9.2%. State-only results are labelled partial. State/administered-local and home-rule delivery taxability are separate; manufacturer coupons reduce payment only. The RDF is $0.28 before July and $0.31 from July 2026, subject to retailer, delivery and state-taxability conditions. Retailer-funded fees do not inflate customer payment.
Formula
Tax = state/administered-local base × their rates + home-rule base × its rate + any verified home-rule tax on the delivery fee. Customer payment includes all delivery charges, subtracts checkout coupons and adds only the RDF charged to that customer.
When to use this calculator
Colorado purchases can involve state-administered and home-rule components with different bases. This calculator keeps them separate and also identifies the supported retail delivery fee, helping avoid an estimate that uses one base and one combined rate for every local component.
Information to prepare
Confirm the city, purchase date and home-rule treatment and prepare the relevant delivery charges. Review whether the delivery fee is actually charged to the customer and whether a verified local tax applies to it. Do not include a fee in the customer's payment solely because it exists in the legal framework.
How to interpret the result
The taxable base can differ from the final payment because of discounts, excluded charges or specially treated items. Assessed tax describes the liability on the transaction, while remaining tax can also depend on valid payments and credits. A combined rate should contain only the components applicable to the location. Exemptions depend on specific facts: a product name resembling a form option is not enough to establish eligibility. Review the item, location, date and charge treatment together before comparing the result with a receipt.
A practical comparison
To reconcile a total, compare administered tax, home-rule tax and the delivery-fee treatment individually. Similar combined rates can produce different amounts when their bases differ. A neighbouring state's calculator is useful for comparison only after its own charges and locality have been identified.
Check your calculation step by step
- Match the figures to the selected period and use USD for monetary inputs. If you start with a document in another currency or covering several periods, resolve that difference before entering a combined amount.
- Calculate the documented case first. Then change one input at a time to compare scenarios. Keep the original values available so a change in the result can be traced to a particular assumption rather than several simultaneous edits.
- Read the component breakdown alongside the formula and examples below. If an official document differs, check the date, base, rounding and omitted concepts before changing a rate or treating the difference as an error.
Continue with a related calculation
These tools cover other questions in United States. Choose the one that matches the amount you want to check:
- Virginia sales tax calculator
Virginia sales tax with locality rates, 1% grocery/hygiene treatment and dated 2026 holiday eligibility.
- Arizona sales tax calculator
Arizona retail TPT with current city components, local grocery rates and separate Phoenix/Goodyear single-item rules.
- Nevada sales tax calculator
Nevada sales/use tax for all 17 counties, correct cent rounding, scoped exemptions and documented tax credits.
- Wisconsin sales tax calculator
Wisconsin sales tax with county/city distinctions, July 2026 resort areas and conditional food/rental levies.
- California sales tax calculator
California sales/use tax using July–September 2026 city rates, correct coupon treatment and delivery exclusions.
- New Jersey sales tax calculator
New Jersey sales/use tax with conditional UEZ/Salem rates, verified exemptions and actual tax credits.
Frequently asked questions
Can the preset replace an address-specific check?
No. Confirm the location, transaction date and item category in the official lookup. Presets cover ordinary sales within the named area, without unlisted special districts or private fees.
How do tax-included prices work?
The entered item price includes the selected percentage taxes, but not additional delivery charges. The Colorado RDF is separate. If the exact receipt total cannot be inverted to a cent-priced base, enter the original before-tax price.
Official sources
- RDF rates and home-rule taxabilityConsulted: 2026-09-13
- RDF retailer exemption and timingConsulted: 2026-09-13
- Retailer payment electionConsulted: 2026-09-13
- State sales-tax guideConsulted: 2026-09-13
- Denver rate componentsConsulted: 2026-09-13
- Boulder 2026 ratesConsulted: 2026-09-13
- Colorado Springs rate componentsConsulted: 2026-09-13
- Aurora / Arapahoe rate componentsConsulted: 2026-09-13
