NT-proBNP optimal range and reference range
Compiled by Alina Radu, founder of Sera, from the published sources below · Last reviewed November 9, 2026
Sera's bands for NT-proBNP:
- Optimal 0 – 125 pg/mL (0 – 125 ng/L); sufficient 125 – 300 pg/mL (125 – 300 ng/L); out of range above 300 pg/mL.
Evidence grade: Established clinical threshold. A band edge that corresponds to a recognised diagnostic, risk or treatment threshold from a major clinical guideline or public-health body.
All units
| Unit | Optimal | Sufficient | Out of range |
|---|---|---|---|
| pg/mL | 0 – 125 | 125 – 300 | above 300 |
| ng/L | 0 – 125 | 125 – 300 | above 300 |
Bounded on the high side only — a low result is not treated as out of range. A low NT-proBNP is the reassuring direction; the thresholds define only a raised result.
What the evidence says
A rule-out test above all: below roughly 125 pg/mL heart failure is very unlikely in someone not acutely unwell. It rises with age and with reduced kidney function independently of the heart, and — the trap — runs LOWER in obesity, so a normal value at a high BMI is less reassuring than it looks. The optimal band ends at the European Society of Cardiology's 125 pg/mL. The acceptable band's upper edge of 300 is the figure guidelines use to rule out acute heart failure in an emergency setting; NICE refers from 400 in primary care.
Sources
- Natriuretic peptide testing and heart failure diagnosis in primary care: diagnostic accuracy study — Taylor CJ, Ordóñez-Mena JM, Lay-Flurrie SL, et al. — British Journal of General Practice, 2023 · Peer-reviewed publicationSets out the guideline thresholds and tests them in UK primary care: the European Society of Cardiology refers at NT-proBNP of 125 pg/mL or more, NICE at 400 or more, and guidelines agree on below 300 to rule out acute heart failure in an emergency setting.
What NT-proBNP measures
The inactive fragment released when the heart muscle stretches, and the standard blood marker of cardiac wall stress.
Its strength is ruling out: a value below about 125 pg/mL makes heart failure very unlikely in someone not acutely unwell. It rises with age and with reduced kidney function independently of the heart, and runs LOWER in obesity, which is the trap — a normal result in someone with a high BMI is less reassuring than it looks.