Ferritin Unit Converter (ng/mL, µg/L, µg/dL, µg/mL, mg/L, pg/mL, nmol/L, pmol/L)
Convert a ferritin result between any two of the 8 units labs use worldwide. Pick your “from” and “to” units, type your value, and hit Convert — no login, no ads.
Recent Conversions
Ferritin Unit Conversion Chart (based on ferritin, MW ≈ 450,000 Da)
ng/mL, µg/L, µg/dL, µg/mL and mg/L are simple decimal-place conversions that apply to any substance. nmol/L and pmol/L use ferritin’s approximate molecular weight and are specific to ferritin.
You just got your blood test back. There’s a number in the ferritin row. And honestly? You have no idea if it’s good, bad, or somewhere in between. Because somehow your lab is using different units from the reference range you found online.
This happens constantly. Labs in different countries — and even different labs in the same country — report ferritin in different units. And unlike simpler measurements, ferritin units can look wildly different.
A result of 50 in ng/mL looks nothing like 0.111 in nmol/L. But they mean exactly the same thing.
Let’s clear all of this up. The converter above handles the math instantly. The rest of this guide explains what the numbers actually mean — and why your ferritin level matters far more than most people realize.
Why Ferritin Has So Many Different Units
Ferritin is a large protein. Really large.
Its molecular weight is approximately 450,000 daltons — which makes it one of the heaviest proteins routinely measured in clinical labs. That massive size is exactly why the same blood level can be expressed in so many wildly different-looking numbers depending on the unit system used.
Clinical labs in the US, Pakistan, India, and most of the developing world traditionally report in ng/mL (nanograms per milliliter). This is also written as µg/L — and those two are mathematically identical. 1 ng/mL = 1 µg/L.
Always. No conversion needed.
Labs using the SI (Système International) system — common in Europe, Australia, and academic research — use molar units like nmol/L or pmol/L. Because ferritin is so heavy, the numbers look tiny in molar units. A completely normal ferritin of 100 ng/mL is only about 0.222 nmol/L.
Same amount of ferritin. Completely different-looking number.
Other units like µg/dL, µg/mL, and mg/L show up in research papers, older lab reports, and specialist settings. They’re less common now, but still around.
Ferritin Unit Conversion Table (Quick Reference)
Based on ferritin MW ≈ 450,000 Da. The most commonly used clinical unit is ng/mL (= µg/L).
| ng/mL (= µg/L) | nmol/L | pmol/L | µg/dL | µg/mL (= mg/L) |
|---|---|---|---|---|
| 10 | 0.0222 | 22.2 | 1.0 | 0.010 |
| 20 | 0.0444 | 44.4 | 2.0 | 0.020 |
| 30 | 0.0667 | 66.7 | 3.0 | 0.030 |
| 50 | 0.1111 | 111.1 | 5.0 | 0.050 |
| 100 | 0.2222 | 222.2 | 10.0 | 0.100 |
| 150 | 0.3333 | 333.3 | 15.0 | 0.150 |
| 200 | 0.4444 | 444.4 | 20.0 | 0.200 |
| 300 | 0.6667 | 666.7 | 30.0 | 0.300 |
| 500 | 1.1111 | 1111.1 | 50.0 | 0.500 |
| 1000 | 2.2222 | 2222.2 | 100.0 | 1.000 |
🔴 Red = potentially low or high · 🟢 Green = commonly targeted optimal range · 🔵 Blue = clinical threshold value
Use the converter at the top for any value not in this table.
What Is Ferritin — and Why Does It Matter So Much?
Ferritin is the protein your body uses to store iron safely. Think of it like a tiny iron vault — it holds iron until your body needs it to make red blood cells, produce energy, grow hair, regulate your immune system, and dozens of other essential jobs.
Here’s the thing most people don’t know. Ferritin levels drop long before hemoglobin does. Your body is smart — it will drain its iron stores first, before letting your red blood cell count fall.
So you can have a perfectly normal hemoglobin level and still be significantly iron deficient. Your CBC looks fine.
But your ferritin is in the basement. And you feel terrible — exhausted, hair falling out, brain foggy, legs restless at night.
This is called iron deficiency without anemia. And it’s massively underdiagnosed. Especially in women.
The ferritin test is the earliest and most sensitive marker of iron deficiency. It catches the problem weeks or months before it shows up anywhere else on a standard blood panel.
Normal Ferritin Levels by Sex and Age
Here’s the frustrating truth: “normal” varies a lot depending on the lab and the reference population used. These are the most widely cited ranges:
| Group | Standard Lab Range (ng/mL) | Functional Optimal (ng/mL) | nmol/L equivalent (optimal) |
|---|---|---|---|
| Adult men | 12–300 | 70–150 | 0.156–0.333 |
| Premenopausal women | 12–150 | 50–100 | 0.111–0.222 |
| Postmenopausal women | 12–300 | 70–150 | 0.156–0.333 |
| Pregnant women | 10–200 | >50 (varies by trimester) | >0.111 |
| Children (1–5 yrs) | 6–67 | Consult paediatrician | — |
| Newborns | 25–200 (up to 650) | N/A | — |
Low Ferritin: Symptoms, Causes, and What That Number Really Means
Low ferritin is one of the most common, most correctable, and most consistently missed diagnoses in modern medicine. It mostly hits women — particularly those who menstruate, are pregnant, or follow plant-based diets. But men get it too, and athletes of both sexes are especially vulnerable.
Symptoms of low ferritin
These tend to appear when ferritin dips below 30–50 ng/mL, even when hemoglobin is still normal:
- Persistent fatigue — the kind that doesn’t get better with sleep. Iron drives mitochondrial energy production. When your iron stores drop, your cells genuinely can’t make ATP efficiently. You’re running on empty at a biological level.
- Hair shedding (telogen effluvium) — hair follicles are metabolically hungry. They’re among the first tissues to get cut off when iron stores fall. Ferritin below 30 ng/mL is strongly linked to diffuse hair loss in women. Most dermatologists now target above 70–80 ng/mL for optimal hair regrowth.
- Brain fog and poor concentration — iron is essential for dopamine synthesis. Low ferritin literally impairs the neurochemistry behind focus, motivation, and mood.
- Restless legs syndrome — that uncomfortable crawling sensation at night that forces you to move your legs? Low ferritin is one of the most common and treatable causes. Most practitioners target above 50–75 ng/mL to resolve it.
- Shortness of breath during exercise — reduced oxygen-carrying capacity even before full anemia sets in.
- Cold hands and feet, pale skin, brittle nails.
- Anxiety and low mood — often misattributed to hormones or stress. Iron repletion can resolve this in 6–8 weeks in many cases.
Common causes of low ferritin
- Heavy menstrual periods — by far the most common cause in premenopausal women
- Pregnancy and postpartum recovery
- Vegetarian or vegan diet (plant-based iron absorbs at about 2–5% vs. 25–35% for heme iron from meat)
- Endurance athletics (runners lose iron through foot-strike hemolysis and sweat)
- Gut malabsorption — celiac disease, Crohn’s, low stomach acid
- Frequent blood donation
- Hidden blood loss (GI bleeding, ulcers)
Ferritin cut-off thresholds that actually matter clinically
| Ferritin Level (ng/mL) | What It Suggests |
|---|---|
| < 12–15 | Confirmed iron deficiency by most lab standards |
| < 30 | Iron deficiency (NICE guidelines); strongly associated with symptoms |
| 30–50 | Borderline — symptoms still common, especially in women and athletes |
| 50–100 | Functional optimal range for most adults (widely targeted in functional medicine) |
| 70–80+ | Target level for optimal hair regrowth and restless legs resolution |
| 300 (men) / 200 (women) | Upper clinical threshold — elevated ferritin; investigate further |
| > 500–1000 | Significantly elevated — hemochromatosis, inflammation, liver disease likely |
High Ferritin: When Your Levels Are Too High
High ferritin gets far less attention than low ferritin. But it’s just as important to understand.
Here’s the catch: elevated ferritin does not automatically mean iron overload. Ferritin is what’s called an acute-phase reactant. That means it rises sharply during inflammation, infection, liver damage, and certain cancers — completely independently of your actual iron stores.
Your body releases ferritin into the blood when tissues are stressed. So a high number might mean iron overload. Or it might mean your body is fighting something.
This is why high ferritin must always be interpreted alongside transferrin saturation (TSAT). If ferritin is high and TSAT is above 45%, that’s a strong signal of true iron overload. If ferritin is high but TSAT is normal or low, the cause is almost certainly inflammatory.
Conditions associated with high ferritin
- Hereditary hemochromatosis — the most common genetic disorder in people of Northern European descent. The body absorbs too much iron and has no way to excrete the excess. Ferritin can climb into the thousands if untreated. Treatment is phlebotomy (regular blood removal) to keep ferritin between 50–100 ng/mL.
- Chronic inflammation — rheumatoid arthritis, inflammatory bowel disease, infections
- Liver disease — hepatitis, cirrhosis, fatty liver disease all release stored ferritin into the blood
- Metabolic syndrome and obesity
- Alcohol use disorder
- Certain cancers — especially leukemia, Hodgkin lymphoma, and GI tumors
- Hemophagocytic lymphohistiocytosis (HLH) — a rare but life-threatening condition where ferritin can reach tens of thousands
Ferritin and Thyroid Health — a Connection Most Doctors Miss
This one surprises a lot of people. Iron and thyroid function are deeply linked.
The enzyme responsible for making thyroid hormones — thyroid peroxidase (TPO) — depends on iron. When ferritin falls below 50–60 ng/mL, TPO activity drops.
T4-to-T3 conversion becomes impaired. And patients experience classic hypothyroid symptoms — fatigue, brain fog, weight gain, hair loss, cold intolerance — even when their TSH looks completely normal.
If you’ve been told your thyroid is fine but you still feel hypothyroid, and nobody has checked your ferritin — that’s a conversation worth having with your doctor. Functional medicine practitioners commonly target ferritin at 90–110 ng/mL for patients with thyroid conditions.
Understanding Your Lab Report: Units Side by Side
Let’s walk through a real example. You get your result: ferritin 75 ng/mL. Your friend in the UK gets theirs: ferritin 0.167 nmol/L. Your cousin’s Australian report says ferritin 75 µg/L.
All three of you have identical ferritin levels. The unit is the only thing that’s different.
Here’s that same value across all units our converter supports:
| Unit | 75 ng/mL expressed as… |
|---|---|
| ng/mL (= µg/L) | 75.0000 |
| µg/L | 75.0000 (identical) |
| µg/dL | 7.5000 |
| µg/mL (= mg/L) | 0.0750 |
| mg/L | 0.0750 |
| pg/mL | 75,000 |
| nmol/L | 0.1667 |
| pmol/L | 166.67 |
The same person. The same blood. Eight different-looking numbers. The converter at the top of this page handles all of them instantly.
Ferritin Conversion in Other Languages
Français (French): 1 ng/mL = 1 µg/L, toujours. Formule : nmol/L = ng/mL ÷ 450. Exemple : 100 ng/mL ÷ 450 = 0,222 nmol/L.
Nederlands (Dutch): 1 ng/mL = 1 µg/L, altijd. Formule: nmol/L = ng/mL ÷ 450. Voorbeeld: 100 ng/mL ÷ 450 = 0,222 nmol/L.
Frequently Asked Questions About Ferritin Conversion
Straight answers to the questions people search for most when comparing ferritin lab results across units and countries.
Is ng/mL the same as µg/L for ferritin?
Yes, exactly the same. 1 ng/mL = 1 µg/L, always, for any substance. These are just two ways of writing the same unit. If your report says either one, the number and reference range are identical.
How do I convert ferritin from ng/mL to nmol/L?
Divide your ng/mL value by 450 to get nmol/L. Example: 100 ng/mL ÷ 450 = 0.2222 nmol/L. Or multiply nmol/L by 450 to get ng/mL. The 450 comes from ferritin’s molecular weight of approximately 450,000 Da (450 kg/mol).
How do I convert ferritin from ng/mL to pmol/L?
Multiply your ng/mL value by 2.222 to get pmol/L. Example: 50 ng/mL × 2.222 = 111.1 pmol/L. To go the other way, divide pmol/L by 2.222.
What is a normal ferritin level in pmol/L?
Normal lab ranges are approximately 26.7–333 pmol/L for men and women (equivalent to 12–150 ng/mL). The functional optimal is roughly 111–222 pmol/L (50–100 ng/mL) for most adults.
My ferritin is 8 ng/mL — is that dangerously low?
A ferritin of 8 ng/mL is significantly low by any standard. Most guidelines define iron deficiency at below 30 ng/mL, and below 12 ng/mL is considered confirmed deficiency by most labs. At 8 ng/mL your iron stores are essentially depleted.
You need to discuss iron supplementation with your doctor urgently. Don’t wait for symptoms to get worse.
My ferritin is “normal” at 18 ng/mL but I feel exhausted. Is that possible?
Absolutely, and you’re not imagining it. The lower boundary of most lab ranges (12 ng/mL) represents statistical population averages, not symptom-free thresholds.
Research consistently shows symptoms of iron insufficiency — fatigue, hair shedding, brain fog — commonly appear when ferritin is below 30–50 ng/mL, well above the lab’s “low” cutoff. At 18 ng/mL, your stores are genuinely depleted even if the report says normal.
My ferritin is 442 ng/mL — should I be worried?
A result of 442 ng/mL is elevated and warrants investigation. The next step is checking your transferrin saturation (TSAT). If TSAT is above 45%, that suggests true iron overload — possibly hemochromatosis.
If TSAT is normal, the elevated ferritin more likely reflects inflammation, liver stress, or metabolic syndrome. Either way, don’t ignore it — get it checked with your doctor.
Why does my UK lab report ferritin in different units than my home country?
Different countries use different unit systems. The UK, Australia, and most of Europe tend to use SI units.
Some report nmol/L, others still use µg/L (which is the same as ng/mL). Use our converter above to translate any result to the unit your reference range uses.
What is the ferritin conversion factor from ng/mL to µg/dL?
Divide by 10. So 50 ng/mL = 5 µg/dL. To convert back, multiply µg/dL by 10 to get ng/mL. This one is simple because it’s just a decimal place shift.
Can ferritin be high even if I’m iron deficient?
Yes. This is the tricky part. Ferritin is an acute-phase reactant — it rises with inflammation, infection, and liver disease regardless of your actual iron stores.
So someone who is genuinely iron deficient may show a falsely normal or even elevated ferritin if they’re also fighting an infection or have active inflammation. This is why doctors often check C-reactive protein (CRP) alongside ferritin to see if inflammation might be masking the true picture.
What ferritin level do I need to stop hair loss?
Most dermatologists and functional medicine practitioners target ferritin above 70–80 ng/mL for optimal hair regrowth. Getting ferritin above this threshold (with appropriate iron supplementation under medical guidance) typically takes 3–6 months of consistent treatment.
What is ferritin’s molecular weight?
Ferritin’s molecular weight is approximately 450,000 daltons (450 kDa), the conventional figure used by most labs and conversion tools for ng/mL-to-nmol/L math. This is an approximation — apoferritin (the iron-free protein shell) actually ranges from about 440,000 to 474,000 Da depending on the source and isoform, which is why molar ferritin conversions are treated as a clinical convention rather than an exact figure.
Is the nmol/L to pmol/L conversion the same for every substance?
Yes. Unlike ng/mL-to-nmol/L (which needs the substance’s molecular weight), converting nmol/L to pmol/L is pure metric prefix scaling: 1 nmol/L = 1,000 pmol/L for any substance, no molecular weight required. Divide pmol/L by 1,000 to go the other way.
Who Usually Needs to Convert Ferritin Units?
More people than you’d think end up on this page — and for good reason:
- Patients comparing lab reports across different countries or different labs that use different unit systems
- Women investigating hair loss — ferritin is one of the first tests ordered when hair is thinning and the cause is unknown
- People with suspected hemochromatosis who need to track ferritin closely in different clinical settings
- Researchers and medical students cross-referencing ferritin data from studies in different countries
- Pregnant women and new mothers monitoring iron status across pregnancy, when reference ranges and units may vary by trimester and by clinic
- Athletes tracking iron status for performance — endurance athletes especially need ferritin well above 50 ng/mL for optimal oxygen transport
- People with chronic fatigue, thyroid issues, or autoimmune conditions who are chasing down causes and comparing notes with online communities or practitioners in other countries
Tips for Getting an Accurate Ferritin Test
The number on your report is only useful if the test was done correctly. A few things that matter:
- Fasting isn’t strictly required for ferritin, unlike glucose or lipids. But some labs prefer you fast for 8–12 hours, and morning testing is standard in many clinics.
- Don’t test during an active infection. Ferritin spikes during illness — even a cold or flu can temporarily push your number up by 50–100%. Wait at least two weeks after recovering.
- Tell your doctor about supplements. Iron supplements taken in the days before the test can slightly raise your result. Some practitioners recommend stopping them 48–72 hours before testing.
- Test CRP at the same time. If CRP is elevated, your ferritin might be falsely high due to inflammation — meaning your true iron stores could be lower than the ferritin number suggests.
- Track it over time. One ferritin result tells you where you are. Three or four results over 12–18 months tell you whether your stores are building, stable, or declining.
Final Word
Ferritin is one of the most important numbers on a blood panel. And one of the most misunderstood.
It’s not just about being anemic or not. It’s about whether your cells have enough iron to make energy, grow hair, regulate your mood, support your thyroid, and carry out hundreds of enzymatic reactions. The difference between ferritin at 15 and ferritin at 80 can be the difference between feeling chronically exhausted and feeling completely fine.
And the units — ng/mL, nmol/L, pmol/L, µg/dL — they’re just different ways of expressing the same measurement. Use the converter at the top of this page whenever you need to translate between them.
Once you know what unit your lab uses, and what range you’re actually aiming for, the number stops being confusing. It just becomes useful information.
