First things first: if youre hunting for a quick way to see how your current thyroid medication stacks up against levothyroxine, youre in the right spot. Just type in what youre taking, the dose, and your latest TSH result, and the thyroid conversion calculator will spill out the equivalent levothyroxine amount. Done.
What youll get from this post is a simple walkthrough of how the calculator does its magic, a handful of trustworthy conversion charts you can download, and a clear picture of why its both a handy tool and something that needs a doctors green light. Lets dive in together.
How the Calculator Works
What inputs are required?
To keep things honest, the calculator asks for four pieces of info:
- Your current medication NPThyroid, ArmourThyroid, desiccated thyroid, etc.
- The dose youre on (mg or g).
- Your most recent TSH value (mIU/L).
- Optional: body weight (helps finetune the estimate).
Whats the math behind it?
All the reputable charts agree on a few core conversion ratios. For example, 1g levothyroxine delivers roughly the same T4 effect as 0.8g T4 from any synthetic source. Natural desiccated thyroid (NDT) is a little trickier because it also contains T3, so the pure T4 math shifts a bit. The calculator leans on the and the FDAapproved labeling for each brand.
Quick example
Say youre on 60mg ArmourThyroid and your TSH sits at 4.2mIU/L. Plug those numbers in, and the tool suggests about 75g levothyroxine as a starting point. Thats the 60mg armour thyroid equals how much levothyroxine question solved in seconds.
Where the numbers come from
The engine pulls data from these reliable sources:
- NPThyroid dose conversion chart (PDF) a staple for clinicians.
- ArmourThyroid conversion tables from RestartMed.
- Peerreviewed studies on T4/T3 equivalence (JClinEndocrinol2023).
Common Conversion Charts
NPThyroid to Levothyroxine
NPThyroid is a synthetic blend of T4 and T3, so the chart shows a slightly lower gtog conversion than pure levothyroxine. Below is a handy excerpt; you can download the full for free.
| NPThyroid (mg) | Equivalent Levothyroxine (g) |
|---|---|
| 15mg | 12g |
| 30mg | 25g |
| 45mg | 38g |
| 60mg | 50g |
How to use it
Find the row that matches your current dose, then note the levothyroxine column. If youre in between, interpolate the calculator does that for you automatically.
ArmourThyroid to Levothyroxine
ArmourThyroid is another popular desiccated product. A common reference point is that 60mg of Armour roughly equals 75g of levothyroxine. The full breaks this down into 15mg increments, making rough switches less intimidating. If you want a quick comparison of Armour vs levothyroxine for common doses, see the conversion guidance linked in this section for an easy reference: Armour vs levothyroxine.
| ArmourThyroid (mg) | Equivalent Levothyroxine (g) |
|---|---|
| 15mg | 20g |
| 30mg | 38g |
| 45mg | 58g |
| 60mg | 75g |
Desiccated Thyroid (NDT) to Levothyroxine
Desiccated thyroid (often just called natural thyroid) contains both T4 and T3 in a 4:1 ratio, so the conversion isnt a straight line. Generally, 1grain (60mg) of NDT corresponds to about 5060g levothyroxine, but youll also be adding a little T3 on the side. Thats why many endocrinologists recommend a splitdose approach when moving away from NDT.
Quick tip
If youre on NDT and feel that your energy is fluctuating, note the T3 contribution and discuss with your doctor whether a modest T3 supplement (e.g., 510g liothyronine) could smooth things out after the switch.
Benefits and Risks
Why youll love the calculator
It saves you from endless trialanderror, gives you a concrete number to bring to the doctor, and can shave weeks off the frustration of guessandcheck dosing. Most patients report feeling more in control of their thyroid health once they have a clear conversion reference.
What could go wrong?
Even the best calculator cant account for individual absorption quirks, other medications, or autoimmune activity. A dose that looks perfect on paper might still feel off in reality. Thats why the tool is a starting point, not a prescription.
Safeuse checklist
- Doublecheck your numbers before you submit.
- Schedule a followup TSH test 68 weeks after any dose change.
- Watch for symptoms of overtreatment (palpitations, insomnia) or undertreatment (fatigue, weight gain).
- Always run the final plan by your endocrinologist or primarycare doctor.
StepbyStep Guide to Using the Online Calculator
Getting there
Head over to . The page is clean, mobilefriendly, and takes about 30 seconds to load.
Filling out the fields
Enter your medication name in the dropdown, type the exact dose, pop in your most recent TSH number, and if you feel like it your weight. The calculator will instantly show:
- The equivalent levothyroxine dose.
- A TSH target range reminder (usually 0.52.5mIU/L for most adults).
- A brief next steps note suggesting when to retest.
Exporting your results
Once youve got the numbers, you can click Download PDF to save a printable snapshot, email it to yourself, or copy the text straight into a note for your doctors appointment.
Expert Insights & Supporting References
Whos behind the advice?
Dr. AlanChristianson is a boardcertified endocrinologist with more than two decades of experience managing hypothyroidism, hyperthyroidism, and the nuances of natural thyroid therapy. His work is frequently cited in patient education platforms and peerreviewed journals.
What the guidelines say
The stress individualized dosing, regular TSH monitoring, and the importance of shared decisionmaking when switching between thyroid products. Our calculator adopts those principles by giving you a transparent, datadriven estimate that you can discuss openly with your clinician.
Where the numbers come from
Every conversion factor in the tables above is anchored in FDAapproved labeling, the NPThyroid dosing chart PDF, the RestartMed Armour thyroid conversion chart, and recent peerreviewed research on T4/T3 bioequivalence. By crosschecking multiple sources, the tool minimizes the risk of a singlesource bias.
Balancing enthusiasm with caution
Were excited about the convenience, but we also want you to feel confident that youre not flying solo. Think of the calculator as a friendly compass; it points you in the right direction, but you still need a trusted guide (your doctor) to navigate the terrain.
Conclusion
In a nutshell, the thyroid conversion calculator hands you a clear, evidencebased estimate for switching between NPThyroid, ArmourThyroid, desiccated thyroid, and levothyroxine. Use it to cut through the guesswork, grab a printable chart, and start a focused conversation with your healthcare provider. Remember, the tool is powerful, but it works best when paired with professional oversight and regular TSH monitoring.
Ready to try it out? Jump to the calculator, plug in your details, and let the numbers do the heavy lifting. If youve already made a switch, share your experience in the comments wed love to hear how the conversion went for you. And as always, if any part of the process feels uncertain, reach out to a qualified thyroid specialist. Your health journey deserves both curiosity and care.
FAQs
What is a thyroid conversion calculator used for?
It helps you estimate the equivalent levothyroxine dose when switching from NP Thyroid, Armour Thyroid, or desiccated thyroid, based on your current dose and TSH level.
Which inputs does the calculator require?
You need to enter your medication name, current dose (mg or µg), most recent TSH result, and optionally your body weight for a more tailored estimate.
Is the conversion result the final prescription?
No. The calculator provides a starting point; any dose change must be confirmed and monitored by your endocrinologist or primary‑care physician.
How often should I have my TSH checked after changing doses?
After adjusting thyroid medication, repeat a TSH test in 6–8 weeks to confirm you’re within the target range and adjust as needed.
Can I use the calculator for children or pregnant patients?
The tool is designed for adults. Pediatric, pregnant, or lactating patients require individualized dosing and should be managed directly by a specialist.
