How long does it take to get Carbon Dioxide results?

Most Carbon Dioxide results are available in 1–3 business days after your specimen arrives at the lab. You'll get an email the moment your results are ready, with everything viewable in your TestWell portal.

How much does a Carbon Dioxide test cost?

Our Basic Metabolic Panel starts at $20.99. That's the all-in price — no copays, no insurance hoops, no surprise bills. HSA and FSA cards are accepted.

Do I need to fast before my Carbon Dioxide test?

Yes — for the most accurate result, fast for 8–12 hours before your blood draw. Water is fine; coffee, food, and supplements are not. Your prep instructions will be included with your order.

Which lab will process my Carbon Dioxide test?

Your test will be processed by Quest Diagnostics, Labcorp, or BioReference depending on which is closest to you and which lab carries the test. All three are CLIA-certified and trusted by hospitals nationwide. You'll choose your lab during checkout from 4,000+ locations.

Metabolic Health

Carbon Dioxide levels: what's normal, high and low

Mostly bicarbonate. Reflects your body's acid-base balance.

Physician reviewed

Results in 1–3 days

4,000+ lab locations

Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026

The short answer

Carbon Dioxide is measured with a standard blood draw after an 8–12 hour fast. A typical reference range is 22.0 – 29.0 mmol/L. At TestWell it's $20.99 all-in as Basic Metabolic Panel, results in 1–3 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.

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Units: mmol/L / mEq/L
Sample: Blood draw
Fasting: 8–12 hours
Results: 1–3 business days
Price: $20.99
Labs: Quest or Labcorp · BioReference in NY/NJ

Carbon Dioxide Reference Range

These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.

Population	Range
age 18+	22.0 – 29.0 mmol/L

Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.

Tools: look up another marker's range · convert lab units

How do you get a Carbon Dioxide test?

Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. Carbon Dioxide is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.

Option	Includes	Price	Per marker
Basic Metabolic Panel	This marker only	$20.99	$20.99

Quest vs. Labcorp for Carbon Dioxide: which lab should you pick?

Both are CLIA-certified national labs and the result is clinically equivalent, so pick whichever location is closer. Your report will print that lab's own reference range, which can differ slightly from the table above.

Lab	Available	Price	Notes
Quest Diagnostics	Yes	$20.99	Choose Quest at checkout; walk-in patient service centers in every state TestWell serves outside NY and NJ.
Labcorp	Yes	$21.99	Choose Labcorp at checkout; walk-in patient service centers in every state TestWell serves outside NY and NJ.
BioReference (NY & NJ)	Yes	$22.99	New York and New Jersey orders route here automatically — state rules keep Quest and Labcorp from accepting self-ordered draws.

Need help choosing a location? Use the lab finder to see draw sites near your ZIP.

Sources

Related Metabolic Health biomarkers

Markers commonly tested alongside Carbon Dioxide.

Glucose Creatinine eGFR BUN ALT AST

Frequently asked

No. TestWell's licensed physician network reviews and approves your order — usually within minutes. You can place an order online without an in-person visit or a referral from your own doctor.

Ready to test your carbon dioxide?

Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $20.99.

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