Heart health
Normal TG:HDL Ratio: Reading a UK Number
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed September 20266 min read
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
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Divide your triglycerides by your HDL. On a UK report both are in mmol/L, which gives a ratio about 2.29 times smaller than the US charts. Research often calls under 2 optimal on the US basis, which is roughly under 0.87 in UK units. No NHS lab publishes a reference range for this ratio.
Not sure which markers you need? Build your test →Your triglycerides are 1.4 and your HDL is 1.3. You divide, get 1.08, and read that anything over 1 is a warning sign.
That warning sign was written for a different unit. Converted properly, 1.08 in UK units is about 2.5 on the American scale, which is a different conversation entirely. This guide covers the conversion, the bands, and the marker the NHS actually uses.
1. What is a normal TG:HDL ratio on a UK report?
The ratio is your triglycerides divided by your HDL cholesterol. Triglycerides are the fat your blood carries after a meal. HDL is the cholesterol that ferries fat back out of your arteries.
For the HDL half of that ratio on its own, see HDL levels by age.
The trap is units. UK labs report both in millimoles per litre. US labs use milligrams per decilitre, and the two convert with different factors: 88.57 for triglycerides, 38.67 for HDL. So the same blood gives a ratio roughly 2.29 times larger on the American scale.
| Band | US basis (mg/dL) | UK basis (mmol/L) |
|---|---|---|
| Often called optimal | below 2 | below about 0.87 |
| Middle ground | 2 to 3.5 | about 0.87 to 1.53 |
| Often called high | above 3.5 | above about 1.53 |
Those bands come from research into insulin resistance, not from a guideline. There is no single agreed cut-off, so treat them as context. Our TG:HDL ratio calculator does the arithmetic and shows both bases at once.
2. A worked example with UK numbers
Take the report from the top of this page. Triglycerides 1.4 mmol/L, HDL 1.3 mmol/L.
- UK ratio: 1.4 divided by 1.3 is 1.08.
- US ratio: multiply by 2.29, which gives about 2.5.
- So this result sits in the middle band, not the high one.
Check the individual numbers too, because they matter more than the ratio. North West London Pathology reads fasting triglycerides under 1.7 mmol/L and non-fasting under 2.0. At 1.4 mmol/L this reader is comfortably inside either.
Fasting matters more for this ratio than for most numbers on your report. Triglycerides climb after a meal and HDL barely moves, so a non-fasting sample inflates the ratio on its own. Our fasting blood test guide covers how long to leave it.
3. Why no UK lab prints a target for it
This surprises people, so it is worth being direct. UK labs mostly do not publish a reference range for HDL either. Gloucestershire Hospitals explains why in one line: reference ranges are not quoted for the other lipid profile parameters. Results are assessed in terms of your overall risk instead.
In other words, a lipid result is not pass or fail. It feeds a risk picture that also includes your age, blood pressure, smoking status and family history. A ratio pulled out of that picture and judged alone loses most of its meaning.
The same lab notes two practical limits. It does not report LDL in non-fasting samples or when triglycerides go above 4.5 mmol/L, and it does not report HDL at all when triglycerides exceed 20 mmol/L. Very high triglycerides break the maths the analyser relies on.
That last figure is not a trivia point. The Royal United Hospitals Bath lipid guidance says triglycerides above 20 mmol/L warrant an urgent discussion with a lipid consultant. Between 10 and 20, it asks for the cause to be treated and the sample repeated. Numbers that high are uncommon, and they are handled by a GP rather than by a ratio.
4. What the NHS tracks instead
Not the TG:HDL ratio. The number UK practice treats to is non-HDL cholesterol, which is your total cholesterol minus your HDL.
“Non-HDL cholesterol is used as an estimation of the total number of atherogenic lipoprotein particles; it is used to risk stratify patients and as a treatment target.”
— Royal United Hospitals Bath, clinical biochemistry
The same guidance sets the targets plainly. For primary prevention the aim is a 40% reduction in non-HDL. For secondary prevention the aim is a non-HDL below 2.5 mmol/L. It also says a full lipid profile should include cholesterol, HDL, non-HDL, LDL and triglycerides, and that it does not need to be fasted.
So if you want one number to watch over time, non-HDL is the one your GP is already watching. Our non-HDL cholesterol guide reads it in detail, and the cholesterol blood test guide covers the whole profile. If it is the triglyceride half of the ratio that is flagged, what a high triglyceride result means reads that number on its own.
5. Which blood test reports both numbers
The markers are triglycerides and HDL cholesterol, both in mmol/L. Helvy's Advanced Heart Health panel (£159) reports both, alongside non-HDL, total cholesterol, LDL, the total to HDL ratio, ApoB, Lp(a), hs-CRP and HbA1c. That gives you the ratio and the numbers the NHS treats to in one sample.
Two honest boundaries. Blood markers describe cardiovascular risk. No blood test can see plaque in an artery, so a good result here is a risk picture rather than an all-clear. And triglycerides read most accurately after a 9 to 12 hour overnight fast, which matters more for this ratio than for anything else on the panel.
Triglycerides and HDL also appear in our General Energy & Wellness panel (£149) if you want a broader first look. The build-my-test tool helps you pick markers.
READY TO TEST?
See both numbers, and the one the NHS treats to
Helvy's home blood tests report triglycerides, HDL and non-HDL in UK units with plain-English context, read as a set rather than one figure at a time. Samples are processed by UKAS-accredited UK labs.
If the HDL side is what dragged your ratio down, our guide to what a low HDL means explains how low is low.
Frequently asked questions
What is a good TG:HDL ratio in UK units?
Research on the US mg/dL basis often calls below 2 optimal and above 3.5 high. In UK mmol/L that is below about 0.87 and above about 1.53. There is no agreed cut-off and no NHS reference range, so read it as context.
Why does the ratio change with units?
Triglycerides and HDL convert between mmol/L and mg/dL with different factors, 88.57 and 38.67. Dividing one by the other leaves a factor of about 2.29, so the US number is always larger for the same blood.
Do I need to fast before this test?
For the ratio specifically, yes, it helps. Triglycerides rise after a meal while HDL stays put, which inflates the ratio. The Royal United Hospitals Bath guidance notes a full lipid profile itself does not need to be fasted.
Is the TG:HDL ratio used by the NHS?
Not as a treatment target. UK practice treats to non-HDL cholesterol, aiming for a 40% reduction in primary prevention and below 2.5 mmol/L in secondary prevention. The TG:HDL ratio comes from research, not from guidelines.
Why does my report not show a normal range for HDL?
Gloucestershire Hospitals says reference ranges are not quoted for most lipid parameters, and that results are assessed in terms of your overall risk instead. Lipids are read as risk, not as pass or fail.
What counts as a normal triglyceride level in the UK?
North West London Pathology reads fasting triglycerides under 1.7 mmol/L and non-fasting under 2.0 mmol/L. Above 4.5 mmol/L many labs stop reporting a calculated LDL, because the calculation stops holding.
Related guides
Non-HDL Cholesterol UK
The number UK practice actually treats to.
Triglyceride Levels by Age UK
The top half of the ratio, read on its own.
HDL Cholesterol UK
The bottom half, and why labs rarely give it a range.
Cholesterol Ratio Blood Test UK
The total to HDL ratio your report probably prints.
Cholesterol Blood Test UK
The whole lipid profile, marker by marker.
Blood Test Reference Ranges UK
Why normal on a lab report is a population range, not a target.