Health
BMI, calorie & wellness calculators
Cholesterol Ratio Calculator
TC/HDL, LDL/HDL, TG/HDL and non-HDL with risk bands, the TG/HDL insulin-resistance flag and Friedewald LDL — risk markers, not a diagnosis. Accurate, instant and free — for United States.
What these mean:
TC/HDL 4, LDL/HDL 2.6, TG/HDL 3, non-HDL 150 mg/dL. Friedewald LDL ≈ 120 mg/dL. Risk markers, not a diagnosis — see a clinician.
Rates as of 2026TC/HDL
4
goodLDL/HDL
2.6
goodTG/HDL
3
≥ 1.5 (IR flag)Non-HDL
150 mg/dL
above 130 goalTG/HDL 3 ≥ 1.5 — insulin-resistance flag
Friedewald LDL
Friedewald LDL ≈ 120 mg/dL.
Friedewald = TC − HDL − (TG ÷ 5), in mg/dL; invalid when triglycerides exceed 400 mg/dL (measure LDL directly). Non-HDL (TC − HDL) is a treatment goal — generally < 130 mg/dL, < 100 at high risk, < 85 at very-high risk.
Risk markers, not a diagnosis
How we calculate this
Reviewed by Reckonist Editorial · Last reviewed July 2026. Figures follow the methods and sources set out in our editorial standards.
Ratios and non-HDL are cardiovascular risk markers, not a diagnosis. Bands per Mayo/NLA/ACC-AHA (2026). General health information, not medical advice — see a clinician.
Mayo Clinic · NLA / ACC-AHA lipid guidance · Friedewald LDL · reference data as of 2026
Tracking metabolic and kidney health too? See the A1C Calculator and the eGFR Calculator.
The four ratios and their risk bands
From one lipid panel — total cholesterol, HDL, LDL and triglycerides — this tool computes TC/HDL, LDL/HDL, TG/HDL and non-HDL, and classifies each into a risk band. Most calculators show only TC/HDL; the full panel — including the TG/HDL insulin-resistance marker and non-HDL as a treatment goal — is the point.
TC/HDL & LDL/HDL
atherogenic ratios
TC/HDL = total ÷ HDL ; LDL/HDL = LDL ÷ HDL
TC/HDL: ideal < 3.5, good < 5, borderline 5–6, high > 6. LDL/HDL ideal < 2. Lower is better.
TG/HDL & non-HDL
metabolic + treatment goal
TG/HDL = trig ÷ HDL ; non-HDL = total − HDL
TG/HDL ≥ 1.5 (mg/dL) flags insulin resistance. Non-HDL goal < 130 mg/dL (< 100 high-risk, < 85 very-high-risk).
- 1Ratios: 200 ÷ 50 = 4.0 (TC/HDL); 130 ÷ 50 = 2.6 (LDL/HDL); 150 ÷ 50 = 3.0 (TG/HDL — ≥ 1.5, an insulin-resistance flag).
- 2non-HDL + Friedewald LDL: non-HDL = 200 − 50 = 150 mg/dL(above the < 130 goal). Friedewald LDL = 200 − 50 − (150 ÷ 5) = 120 mg/dL — close to the measured 130; the small gap is exactly why Martin-Hopkins is more accurate.
TG/HDL — an insulin-resistance proxy
The triglyceride-to-HDL ratio is more than a lipid number: in mg/dL, a TG/HDL at or above 1.5 is a widely-cited proxy for insulin resistance, and it is often one of the better predictors of cardiovascular risk. It is the angle single-ratio calculators leave out.
The unit trap — 1.5 is a mg/dL figure
Pair it with a glycemic marker
Non-HDL as a goal, and how LDL is derived
Non-HDL cholesterol (total − HDL) captures every atherogenic particle, not just LDL, so guidelines increasingly treat it as the better target: generally below 130 mg/dL, below 100 at high risk, below 85 at very-high risk. Because it needs only total cholesterol and HDL, it is computable even when LDL is missing. LDL itself is usually derived, via Friedewald: LDL = total − HDL − (triglycerides ÷ 5) — which is invalid above 400 mg/dL of triglycerides, where LDL must be measured directly.
mg/dL vs mmol/L — two different factors
Cholesterol (total, LDL, HDL) converts with a factor of 38.67 (divide mg/dL by 38.67 for mmol/L). Triglycerides use 88.57, because the molecule is heavier. Applying one factor to a whole panel is a classic error — and it is why the TG/HDL 1.5 cutoff (a mg/dL figure) does not transfer unchanged to mmol/L. This tool labels every value with its unit and converts each with the correct factor.
Frequently asked questions
The total-cholesterol-to-HDL (TC/HDL) ratio is the one most often quoted: below about 3.5 is ideal, under 5 is good, 5–6 is borderline, and above 6 is high. LDL/HDL is ideal below 2. These come from dividing your total or LDL cholesterol by your HDL, so raising HDL or lowering LDL both improve the ratio. Lower is better — and a ratio is a risk marker, not a diagnosis.
The triglyceride-to-HDL (TG/HDL) ratio is an underappreciated metabolic marker: in mg/dL units, a ratio at or above 1.5 is a commonly cited proxy for insulin resistance, and it is often one of the better predictors of cardiovascular risk. Important caveat: the 1.5 cutoff is defined for mg/dL. If your lab reports mmol/L, the number is different — convert before comparing. For a complementary glycemic view, pair it with an A1C.
Non-HDL cholesterol is simply total cholesterol minus HDL — it captures every atherogenic ("bad") particle, not just LDL, so many guidelines treat it as a better target than LDL alone. It is framed as a treatment goal: generally below 130 mg/dL, below 100 mg/dL if you are at high risk, and below 85 mg/dL at very-high risk (per NLA / ACC-AHA). It needs only total cholesterol and HDL, so you can compute it even when LDL is missing.
Most labs derive LDL rather than measure it directly, using Friedewald: LDL = total cholesterol − HDL − (triglycerides ÷ 5), in mg/dL. It becomes unreliable when triglycerides exceed 400 mg/dL, in which case LDL should be measured directly. The Martin-Hopkins method swaps the fixed ÷5 for an adjustable factor and is more accurate at low LDL or high triglycerides — which is why a derived LDL can differ slightly from a measured one.
Cholesterol (total, LDL, HDL) converts with a factor of 38.67 — divide mg/dL by 38.67 for mmol/L. Triglycerides use a different factor, 88.57, because their molecule is heavier. That difference is why you cannot apply one conversion to a whole panel, and why the TG/HDL 1.5 insulin-resistance cutoff (a mg/dL figure) does not carry over unchanged to mmol/L. This calculator converts each value with the correct factor before computing anything.
Yes — it is completely free with no sign-up, and every calculation runs entirely in your browser. Nothing you enter is sent to a server or stored. It is general health information for education, not medical advice, and the ratios it shows are cardiovascular risk markers, not a diagnosis.
Method, standards & references
Methodology: TC/HDL = total ÷ HDL; LDL/HDL = LDL ÷ HDL; TG/HDL = triglycerides ÷ HDL (a mg/dL insulin-resistance proxy at ≥ 1.5); non-HDL = total − HDL, a treatment goal (< 130 general, < 100 high-risk, < 85 very-high-risk). Friedewald LDL = total − HDL − (triglycerides ÷ 5), invalid above 400 mg/dL. Units: cholesterol ÷ 38.67, triglycerides ÷ 88.57. Bands held in versioned config per Mayo / NLA / ACC-AHA; all calculations run client-side and nothing is stored. Reference data as of 2026. Risk markers, not a diagnosis.
Cross-links
How we calculate this
Reviewed by Reckonist Editorial · Last reviewed July 2026. Figures follow the methods and sources set out in our editorial standards.
These ratios and non-HDL are cardiovascular risk markers computed with standard formulas and bands per Mayo / NLA / ACC-AHA (2026). Lower ratios are generally better, but this is general health information for education, not medical advice, and not a diagnosis. Treatment decisions depend on your full clinical picture — always confirm with a clinician.
Keep going
Same-category tools follow this colour; a cross-category link keeps its own.