Key takeaways
- Your cholesterol ratio is your total cholesterol divided by your HDL ("good") cholesterol, calculated from the same lipid profile blood sample.
- A lipid profile at Blood London, which reports the figures needed to work out your ratio, costs £72.50 plus the £50 blood draw, with results back in 1 day.
- A lower ratio is generally better, because it means more of your cholesterol is the protective HDL type.
- NHS guidance generally describes a ratio above 6 as high, though a doctor weighs it alongside your wider risk factors rather than as a number on its own.
- The ratio feeds into overall cardiovascular risk scoring, such as QRISK3, rather than being used as a stand-alone diagnostic figure.
- Two people can have the same total cholesterol and a different ratio, because the ratio depends on how that total is split between HDL and everything else.
Your cholesterol ratio is your total cholesterol divided by your HDL cholesterol. A lower number is generally better, since it shows more of your cholesterol is the protective HDL type, and NHS guidance generally describes a ratio above 6 as high. Both figures come from one lipid profile blood test.
Book a lipid profile at 117a Harley Street: £72.50 plus the £50 blood draw, results back in 1 day.
How is the cholesterol ratio calculated?
The ratio is simply total cholesterol divided by HDL cholesterol, both measured from the same blood sample on a standard lipid profile. For example, a total cholesterol of 5 mmol/L and an HDL of 1.25 mmol/L would give a ratio of 4. The ratio is a way of relating two results rather than a separately measured marker: your laboratory report shows both figures, and if the ratio itself is not printed, you or your doctor can work it out by dividing one by the other. If you only need the HDL cholesterol figure on its own, it can be tested by itself for £58.13 plus the £50 blood draw, with results in 1 day.
Why does the ratio matter alongside the individual numbers?
Because two people can have the same total cholesterol but very different risk, depending on how much of that total is protective HDL. Someone with a high total cholesterol but also high HDL can have a lower ratio, and therefore a different risk picture, than someone with a lower total cholesterol but very low HDL. This is why doctors often look at the ratio as well as the individual LDL, HDL and total figures rather than any one number in isolation.
| Reading | What it generally suggests |
|---|---|
| Lower ratio | A greater share of protective HDL cholesterol relative to the total |
| Higher ratio | A smaller share of HDL relative to the total, generally regarded as less favourable |
| Above 6 | Described by NHS guidance as a high ratio |
General pattern only. Your doctor interprets your ratio alongside your full cardiovascular risk picture, not as a stand-alone result.
Is a lower ratio always better?
Broadly, yes, a lower ratio is generally regarded as more favourable, but it isn't judged in isolation. Your doctor also looks at your LDL and non-HDL cholesterol directly, plus your blood pressure, smoking status, weight, family history and other risk factors, usually together in a risk score such as QRISK3. The ratio adds useful context to the individual figures rather than replacing them; our guide to normal cholesterol levels explains each one.
Can I improve my cholesterol ratio?
Since the ratio reflects both your total cholesterol and your HDL, anything that lowers total cholesterol or raises HDL can improve it. Diet, regular activity, stopping smoking and reaching a healthy weight are the usual starting points, and some people also need medication. Whether lifestyle change alone is enough, or treatment is also needed, is a decision for your doctor based on your full risk picture rather than the ratio alone.
Are there tests that look at heart risk in more detail than a standard ratio?
Yes. The advanced heart health blood test adds apolipoproteins A1 and B, lipoprotein(a), high-sensitivity CRP and Lp-PLA2 to a full lipid profile (£495 plus the £50 blood draw, results in up to 3 working days; a 10 to 12 hour fast is preferred). Cardiovascular Risk Profile 1 covers a similar set of markers (£471.25 plus the £50 blood draw, results in 3 days). These are for people who want more depth than the ratio alone provides, not a replacement for it. If you would like a specialist opinion on your heart risk, the cardiology clinic at Medical Express Clinic can review your results with you. Chest pain, especially with breathlessness, sweating or pain spreading to the arm or jaw, is an emergency: call 999.
How cholesterol testing works at our Harley Street clinic
A lipid profile, which gives you both the total and HDL figures needed for your ratio, costs £72.50 plus the £50 blood draw. Most people do not need to fast beforehand. Results are sent by email, usually within 1 day, and you can walk in or book online at 117a Harley Street, seven days a week, with no GP referral needed. The lipid profile can be booked on its own or alongside any of our other private blood tests in London in the same visit. You can add a doctor review of your report to your test for £75.
Book your lipid profile online or walk in at 117a Harley Street: £72.50 plus the £50 blood draw, results by email in 1 day. Start your booking.
Frequently asked questions
What is a normal cholesterol ratio?
There isn't a single number that applies to everyone, but NHS guidance generally describes a ratio above 6 as high. Your doctor interprets your ratio alongside your overall risk factors rather than against one cut-off.
Is the cholesterol ratio more important than total cholesterol?
Neither figure is used alone. The ratio adds context to your total cholesterol by showing how much of it is the protective HDL type, and your doctor looks at both together with your wider risk picture.
Does the cholesterol ratio use non-HDL cholesterol instead of total?
The standard ratio most commonly quoted uses total cholesterol divided by HDL. Non-HDL cholesterol is a separate figure some doctors also use, reported directly on your lipid profile rather than as part of the ratio calculation.
Can my ratio be high even with normal total cholesterol?
Yes. If your HDL is low, your ratio can be higher than expected even when your total cholesterol looks acceptable, which is one reason the ratio is calculated in the first place.
Do I need a separate test to get my cholesterol ratio?
No. A standard lipid profile measures both total and HDL cholesterol, so the ratio is calculated from the same sample without any extra testing.
How often should I recheck my ratio?
That depends on your risk factors and whether you're on treatment, and is best agreed with your doctor. The NHS Health Check, which includes a cholesterol test, is offered every 5 years to adults aged 40 to 74; people on treatment are usually tested more often.
References
- Cardiovascular disease: risk assessment and reduction, including lipid modification (NICE)
- High cholesterol (NHS)
- High cholesterol: cholesterol levels (NHS)
- QRISK3 risk calculator (ClinRisk)