Monocyte to HDL Cholesterol Ratio (MHR) Calculator
Monocyte to HDL Cholesterol Ratio (MHR) Calculator
The monocyte count divided by HDL cholesterol — and the only thing that matters about it. The same patient scores 0.45 or 11.69 depending on which units the two numbers are in, so a cut-off quoted without its units means nothing.
Monocyte to HDL Cholesterol Ratio (MHR)
Monocytes ÷ HDL, units declaredMonocytes 0.52 ×10⁹/L, HDL cholesterol 1.15 mmol/L
The formula is trivial. The units are the whole problem.
This calculator reports it as cells/µL ÷ mg/dL, the convention almost every published cut-off is written in.
MHR(cells/µL ÷ mg/dL) = 25.863 × MHR(×10⁹/L ÷ mmol/L)
because 1 ×10⁹/L = 1,000 cells/µL and 1 mmol/L = 38.665 mg/dL, and 1,000 ÷ 38.665 = 25.863
- why 25.863 and not some round number
- the two unit changes push in opposite directions. Converting monocytes from ×10⁹/L to cells/µL multiplies by 1,000; converting HDL from mmol/L to mg/dL multiplies the denominator by 38.665. The net factor is their quotient
- 38.665
- cholesterol has a molar mass of 386.65 g/mol, so 1 mmol/L is 0.38665 g/L is 38.665 mg/dL. The same factor the cholesterol converter on this site uses, usually quoted as the reciprocal 0.0259
- a third convention exists
- some studies divide the monocyte PERCENTAGE by HDL instead of the count. That is a different quantity again — the NHANES reference intervals for it are 3.1–10.1 in men against 0.175–0.709 for the count-based version — and it is not what this calculator computes
- the founding paper states no units at all
- Kanbay and colleagues’ 2014 chronic kidney disease study, which introduced the ratio, says only that “M/H ratio was calculated for all patients” and gives neither the units nor the tertile boundaries. The original paper cannot be reproduced from its own text
Worked example
Monocytes 0.52 ×10⁹/L, HDL cholesterol 1.15 mmol/L
0.52 ×10⁹/L = 520 cells/µL
1.15 mmol/L × 38.665 = 44.46 mg/dL
520 ÷ 44.46 = 11.69 in the conventional cells/µL ÷ mg/dL units
The same patient in SI units: 0.52 ÷ 1.15 = 0.452
11.69 ÷ 0.452 = 25.863 — the factor, confirmed both ways
Now the error this page exists to prevent. Canpolat's atrial fibrillation cut-off is 11.48. Against 11.69 this patient is just above it. Against 0.452 they are below it by a factor of twenty-five, and the same patient reads as low risk
And note the other direction: 11.69 sits comfortably inside the healthy-adult reference span of 3.49–18.34. The 'high risk' threshold from that AF cohort is an ordinary value in the general population
The same patient, three ways of writing it
| Convention | Monocytes | HDL | MHR |
|---|---|---|---|
| Conventional — the one this page reports | 520 cells/µL | 44.46 mg/dL | 11.69 |
| SI | 0.52 ×10⁹/L | 1.15 mmol/L | 0.452 |
| Mixed (×10⁹/L over mg/dL) — meaningless but frequently produced by accident | 0.52 | 44.46 | 0.0117 |
| Mixed (cells/µL over mmol/L) — likewise | 520 | 1.15 | 452 |
Published figures, with their units attached
| Source | Population | Value | Units |
|---|---|---|---|
| NHANES reference intervals (Lipids Health Dis, 2025) | 6,757 apparently healthy adults | Men 0.175 – 0.709; women 0.135 – 0.511 (2.5th–97.5th percentile) | ×10⁹/L ÷ mmol/L |
| The same, converted | — | Men 4.53 – 18.34; women 3.49 – 13.22 | cells/µL ÷ mg/dL |
| Canpolat et al., Europace 2015 | 402 patients before cryoballoon ablation for atrial fibrillation | Cut-off 11.48 (sensitivity 85%, specificity 74%, AUC 0.853); cohort median 10.6 | cells/µL ÷ mg/dL |
| Kanbay et al., Int Urol Nephrol 2014 — the original | 340 patients with stage 1–5 CKD | Top vs bottom tertile: HR 2.24 fatal and 4.91 composite cardiovascular events | Not stated in the paper |
| Monocyte-percentage variant (Lipids Health Dis, 2025) | 6,817 apparently healthy adults | Men 3.116 – 10.097; women 2.331 – 7.000 | monocyte % ÷ mmol/L — a different quantity |
Catching a unit error before it becomes a conclusion
| If your MHR is about… | You are probably in… | Check |
|---|---|---|
| 0.1 – 1.0 | ×10⁹/L ÷ mmol/L (SI) | Multiply by 25.863 to compare with a cut-off from the conventional literature |
| 3 – 20 | cells/µL ÷ mg/dL (conventional) | This is the convention nearly every published cut-off uses |
| 0.005 – 0.03 | Mixed: ×10⁹/L ÷ mg/dL | The monocyte count was not converted. Multiply it by 1,000 |
| 200 – 900 | Mixed: cells/µL ÷ mmol/L | The HDL was not converted. Multiply it by 38.665 |
A ratio whose value is a statement about units
The monocyte-to-HDL cholesterol ratio has a plausible rationale. Monocytes drive the inflammatory arm of atherogenesis; HDL particles carry out reverse cholesterol transport and have anti-inflammatory and antioxidant effects on the endothelium; dividing one by the other is an attempt to capture the balance between them in a single number available from tests almost everyone already has. Since Kanbay and colleagues introduced it in 2014 in chronic kidney disease it has been reported as associated with outcomes in coronary disease, atrial fibrillation, stroke, diabetes, vasculitis and a long list besides.
It also has a problem that most of that literature does not acknowledge, and which makes the majority of published cut-offs unusable as printed. Neither term has a settled unit. Monocyte counts appear as ×10⁹/L in most of the world and as cells per microlitre in much of the cardiology literature, a factor of a thousand. HDL cholesterol appears as mmol/L or mg/dL, a factor of 38.665. The two errors push in opposite directions, so the net factor between the two common conventions is 25.863 — and mixing them gives values that are wrong by 1,000 or by 38.7 in either direction. The same patient can be written as 0.452, 11.69, 0.0117 or 452, and only two of those four are conventions anyone uses.
This is not a theoretical hazard. The atrial fibrillation study that produced the most widely quoted cut-off, 11.48, labels its monocyte counts ‘×10⁹/L’ in Table 1 while printing values of 447.6 and 564.3, which are plainly cells per microlitre; dividing the printed 564.3 by the printed HDL of 35.9 mg/dL reproduces the paper’s own stated ratio of 15.6, confirming that the numbers are right and the label is wrong. A reader who takes 11.48 at face value and applies it to a count in ×10⁹/L will be out by a factor of 25,863. And the founding paper is worse: Kanbay’s study reports its findings by tertile and never states the units or the tertile boundaries at all, so its hazard ratios cannot be attached to any particular value of the ratio.
Because of all this, the bands on this page are not a risk threshold. They are the 2.5th to 97.5th percentile span from 6,757 apparently healthy NHANES adults — the only genuine reference interval this ratio has — converted from the mmol/L convention it was published in into the cells/µL convention almost every cut-off is written in. It is sex-specific: 4.53 to 18.34 in men, 3.49 to 13.22 in women. Setting the published cut-offs against it is instructive. Canpolat’s 11.48, derived by ROC analysis to separate recurrence from non-recurrence after ablation, sits comfortably inside the healthy reference interval in both sexes. That is characteristic of a cut-off optimised on a selected cohort: it separates that cohort, and it describes nothing about the general population.
There is a third convention as well, in which the monocyte PERCENTAGE rather than the count is divided by HDL. The same NHANES paper publishes reference intervals for both and they are not comparable — 3.1 to 10.1 in men for the percentage version against 0.175 to 0.709 for the count version. Before comparing any MHR with any published figure, three things have to match: the monocyte unit, the HDL unit, and whether the numerator is a count or a percentage.
Underneath the units, the honest position on the ratio itself is the same as for the rest of this family. It is a research and epidemiological measure with no validated role as a decision rule, it appears in no guideline, and a value outside the reference interval is a prompt to look at its two components — a monocytosis needs a blood film and a cause, a low HDL needs a lipid assessment — rather than a finding in its own right.
Frequently asked questions
How is the monocyte-to-HDL ratio calculated?
The absolute monocyte count divided by the HDL cholesterol concentration. The arithmetic is trivial and the units are not: this calculator reports it in cells per microlitre over mg/dL, which is the convention nearly every published cut-off uses, and accepts either unit on either input.
Why do published MHR values differ so much?
Almost entirely because of units. Converting monocytes from ×10⁹/L to cells/µL multiplies by 1,000 and converting HDL from mmol/L to mg/dL multiplies the denominator by 38.665, so the net factor between the two common conventions is 25.863. A value of 0.45 and a value of 11.69 can be the same patient.
What is a normal MHR?
In 6,757 apparently healthy NHANES adults the 2.5th to 97.5th percentile span was 0.175–0.709 in men and 0.135–0.511 in women, using monocytes in ×10⁹/L over HDL in mmol/L. Converted to the cells/µL over mg/dL convention that is 4.53–18.34 in men and 3.49–13.22 in women.
Is there a cut-off for high risk?
None that transfers. The most quoted figure, 11.48, comes from 402 patients having cryoballoon ablation for atrial fibrillation and was derived by ROC analysis on that cohort — and it falls inside the healthy adult reference interval for both sexes. This page publishes it in a table with its units and its cohort, and does not use it as a band.
Does it matter whether the numerator is the monocyte count or the percentage?
Yes, they are different quantities with different reference intervals. The same NHANES analysis gives 0.175–0.709 in men for the count-based ratio and 3.116–10.097 for the percentage-based one. Studies using the two are not comparable, and this calculator uses the count.
Should an abnormal MHR change anything?
Not in itself. It is a research measure absent from every guideline and never validated as a decision rule. A ratio outside the reference interval is a reason to look at its two components separately — a monocyte count above 1.0 ×10⁹/L needs a film and a cause, and a low HDL needs a lipid assessment — not a finding to act on directly.
Related calculators
References
- Kanbay M, Solak Y, Unal HU, et al. Monocyte count/HDL cholesterol ratio and cardiovascular events in patients with chronic kidney disease. Int Urol Nephrol. 2014;46(8):1619–1625.
- Canpolat U, Aytemir K, Yorgun H, et al. The role of preprocedural monocyte-to-high-density lipoprotein ratio in prediction of atrial fibrillation recurrence after cryoballoon-based catheter ablation. Europace. 2015;17(12):1807–1815.
- Monocyte-to-HDL ratio (MHR) as a novel biomarker: reference ranges and associations with inflammatory diseases and disease-specific mortality. Lipids Health Dis. 2025;24:10.1186/s12944-025-02755-8.
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.