This cholesterol calculator turns a standard lipid panel into the derived numbers clinicians actually compare: the total-to-HDL ratio, LDL/HDL ratio, non-HDL cholesterol and triglyceride ratios — plus Friedewald LDL when a panel reports only total, HDL and triglycerides.
Desirable reference points (general adult guidance): TC/HDL under ~3.5 is considered optimal-leaning; non-HDL is typically targeted about 30 mg/dL above your LDL goal. Risk is multifactorial — your clinician reads lipids with age, pressure, glucose and history in one view.
Why Ratios Exist
Absolute numbers hide balance: a total of 220 means one thing with HDL 80 and another with HDL 35. The TC/HDL ratio compresses that balance (lower is better; under ~3.5 is the commonly cited sweet spot), while non-HDL (total minus HDL) captures every atherogenic particle class at once and works even on non-fasting samples. Friedewald LDL — TC − HDL − TG/5 — is how most labs still derive LDL, failing when triglycerides exceed ~400 mg/dL (or run very low), where direct assays take over. The other pillar of the standard risk panel is your Blood Pressure reading. Part of our Health Calculators collection.
Worked Example (Verified)
Panel: TC 200, HDL 55, LDL 120, TG 150 mg/dL:
- TC/HDL = 200 ÷ 55 = 3.64 — close to, not quite at, the 3.5 benchmark
- LDL/HDL = 2.18 · Non-HDL = 145 mg/dL · VLDL estimate = 150 ÷ 5 = 30 mg/dL
- Friedewald LDL = 200 − 55 − 30 = 115 mg/dL vs the reported 120 — small gaps between calculated and direct LDL are normal laboratory life, especially as triglycerides climb
Reading the Whole Panel
| Measure | Generally desirable | Notes |
|---|---|---|
| Total cholesterol | < 200 mg/dL | Context decides — see ratios |
| LDL | < 100 mg/dL optimal | Targets tighten with risk (70 in high-risk care) |
| HDL | ≥ 40 (men), ≥ 50 (women) | Higher is generally protective-leaning |
| Triglycerides | < 150 mg/dL | Fasting matters most here |
| TC/HDL ratio | < 3.5 optimal-leaning | Risk climbs steadily above ~5 |
| Non-HDL | LDL goal + 30 | Valid non-fasting; counts all atherogenic fractions |
Related Tools
- Blood Pressure Calculator — the risk panel’s other half
- A1C Calculator — metabolic panel companion
- Health Calculators — the full collection
Frequently Asked Questions
What is a good cholesterol ratio?
TC/HDL below about 3.5 is considered optimal-leaning; average US adults sit near 4.5–5, and risk rises with the ratio. LDL/HDL under ~2.5 is a common companion benchmark.
How is LDL calculated (Friedewald)?
LDL = total cholesterol − HDL − triglycerides/5 (mg/dL). It estimates VLDL as TG/5, and it’s unreliable when TG exceeds ~400 mg/dL, in which case labs use direct LDL or newer equations (Martin/Hopkins, Sampson).
What is non-HDL cholesterol?
Total cholesterol minus HDL — LDL + VLDL + remnants in one number, representing all artery-wall-bound fractions. It needs no fasting and is a secondary target in many guidelines (your LDL goal + 30 mg/dL).
My LDL is fine but triglycerides are high. Do ratios still help?
Yes — non-HDL and the TC/HDL ratio catch exactly that pattern, where LDL alone looks calm while total atherogenic burden isn’t. High triglycerides also break Friedewald LDL’s assumptions (noted above).
Should I use mg/dL or mmol/L?
This calculator uses mg/dL (US convention). For mmol/L panels, multiply cholesterol values by 38.67 to get mg/dL (triglycerides by 88.57), or ask the lab for the US-unit report.
Is this cholesterol calculator free?
Yes — free and instant, for information; lipid management decisions belong with your clinician.