Thyroid Tools & Calculators
Free tools built by a thyroid doctor to help you understand your labs, track your progress, and take control of your thyroid health.
Each tool below was designed based on years of clinical experience treating thyroid patients and reflects the optimal ranges and ratios used in functional and integrative medicine, not just the standard reference ranges.
Optimal Thyroid Lab Test Calculator
Enter your thyroid lab values and instantly see whether your results fall within the optimal range, not just the standard reference range. Covers all seven key thyroid markers: TSH, free T3, free T4, total T3, reverse T3, TPO antibodies, and thyroglobulin antibodies.
Reverse T3 Ratio Calculator
Your reverse T3 level alone doesn’t tell the full story. What matters is the ratio between your free T3 and reverse T3. This calculator computes your reverse T3 ratio and tells you whether it falls within the optimal range used in functional medicine.
TI-RADS Thyroid Nodule Calculator
Score your thyroid nodule using both the ACR TI-RADS system (TR1 through TR5) and the ATA Sonographic Pattern system side by side. Enter your ultrasound features and nodule size and get your risk category, malignancy estimate, and biopsy size threshold from both major classification systems at once.
Bethesda Thyroid Biopsy Calculator
Got your thyroid biopsy results back? Enter your Bethesda category (1 through 6) to see your cancer risk percentage from both the 2017 and 2023 versions of the Bethesda System, whether molecular testing (Afirma, ThyroSeq, ThyGenX) is appropriate, and whether you need surgery or surveillance. Optional modifiers for TI-RADS score, family history, and radiation history refine the recommendation further.
Thyroid Nodule Growth Calculator
Had two ultrasounds on the same nodule? Enter the three dimensions and dates from each scan and this calculator computes your volume change, per-dimension growth, annual growth rate, and a clear yes-or-no answer on whether your nodule meets the ATA significant growth criteria that warrant repeat biopsy or re-evaluation. Optional Bethesda category and TI-RADS score refine the next-step recommendation.
Thyroid Cancer Staging Calculator
Had a thyroidectomy for thyroid cancer and trying to make sense of your pathology report? Enter your cancer subtype (differentiated, medullary, or anaplastic), your age, and your TNM classification (tumor size, lymph node status, distant spread) and this calculator translates it into your AJCC 8th Edition stage with your 5-year survival rate from SEER population data, the standard treatment approach, and what you can do to support your thyroid through treatment and recovery.
Thyroid Medication Conversion Calculator
Switching thyroid medications or wondering what an equivalent dose would be? Enter your current medication (or combination of medications), pick the one you want to switch to, and instantly see your equivalent dose. Toggle between Dr. Childs’ recommended conversions and conventional conversion metrics.
Levothyroxine Dosage Calculator
Get a weight-based starting dose of levothyroxine for hypothyroidism, Hashimoto’s, subclinical hypothyroidism, or post-thyroidectomy. The calculator adjusts automatically for pregnancy, age, heart conditions, and weight using the 1.6 mcg/kg/day full-replacement formula from ATA and AACE guidelines.
Levothyroxine Dose Adjustment Calculator
Already on levothyroxine and wondering if your dose needs to change? Enter your most recent TSH, your current dose, and your clinical scenario, and this calculator tells you whether to go up, stay the same, or come down. It uses ATA/AACE step-wise adjustment rules with pregnancy-specific and cancer-specific TSH targets built in.
Armour Thyroid & NDT Dosage Calculator
Get a weight-based starting dose of Armour Thyroid, NP Thyroid, or compounded NDT using Dr. Childs’ clinical conversion math, which values T3 at 3x T4 potency and gives you more NDT than the conventional pharmaceutical chart. The calculator returns your dose in grains and milligrams, breaks down the T4 and T3 components, and builds a 4-week titration schedule so the T3 doesn’t hit you all at once.
Pregnancy TSH Calculator
Pregnant or planning to be and on thyroid medication? This calculator checks whether your TSH is optimal for your trimester and provides levothyroxine dose adjustments if it isn’t. It uses the 2017 ATA Pregnancy Guidelines as the baseline and lets you compare three TSH targets: Dr. Childs’ Optimal range, a Functional range, and the ATA Standard range.
Missed Thyroid Dose Calculator
Missed a dose of Synthroid, levothyroxine, Cytomel, or Armour Thyroid and wondering how much it matters? This calculator uses T4’s 7-day half-life to estimate how far your serum levels have dropped based on the number of days missed, your medication type, and your daily dose. It also flags pregnancy and thyroid cancer cases that need faster follow-up.
T4 to T3 Ratio Calculator
On T4-only medication and still symptomatic? This calculator tells you how much T3 to add to your current T4 dose to hit a physiological 5:1 T4-to-T3 ratio, matching the 80/20 output of a healthy thyroid gland. Built for patients on T4 monotherapy with poor conversion, Hashimoto’s, or post-thyroidectomy who do better on combination therapy.
Hypothyroid Calorie Calculator
Standard calorie calculators don’t account for the metabolic suppression caused by hypothyroidism, which can reduce your BMR by 5% to 40%. This calculator uses the Mifflin-St Jeor equation with a thyroid-specific adjustment layer and factors in menopause, insulin resistance, plateau status, and a history of crash dieting.
Hypothyroid Macro Calculator
Find out how much protein, carbs, and fat to eat per day with hypothyroidism. Protein is anchored to grams, not a percentage of calories, so it doesn’t undershoot when you’re in a deficit. Choose from five macro patterns (Thyroid-Optimized, Balanced, Higher Protein, Lower Carb, and Mediterranean) with a sixth Keto option if you flag insulin resistance or PCOS.
Hypothyroid Symptom Quiz
Not sure if your symptoms point to a thyroid problem? This weighted screening quiz covers symptoms organized by body system, from metabolic and digestive to skin, hair, cardiovascular, and reproductive. It also factors in risk modifiers like age, sex, and family history. Scoring is built on the specificity principles from the Zulewski clinical score and the Colorado Thyroid Disease Prevalence Study.
Hashimoto’s Symptom Quiz
Wondering if your thyroid symptoms are autoimmune? This quiz weights symptoms by how specifically they point to Hashimoto’s, not just low thyroid function, and factors in autoimmune-specific risk factors like family history, other autoimmune conditions, postpartum status, and prior antibody results. If you’ve already tested positive for thyroid antibodies, the quiz adjusts your tier accordingly.
Hyperthyroid Symptom Quiz
Experiencing a racing heart, unexplained weight loss, or anxiety that won’t quit? This weighted screening quiz combines your symptoms with lab signals and risk factors to distinguish overt hyperthyroidism, subclinical hyperthyroidism, and thyroid hormone over-replacement. It’s organized by body system and flags the patterns most specific to an overactive thyroid or excess thyroid medication.
Graves’ Disease Symptom Quiz
Wondering if your overactive thyroid is Graves’ disease? This quiz combines hyperthyroid symptoms with Graves’-specific tells like eye signs, autoimmune family history, and antibody status to distinguish Graves’ from other causes of hyperthyroidism. It’s designed for adults trying to figure out whether antibody testing or specialist referral is the right next step.
Can I Stop Taking Levothyroxine? (Quiz)
Wondering if you can safely come off levothyroxine, Synthroid, NDT, or any thyroid medication? This 10-question quiz uses research-backed predictors to estimate your odds of discontinuing thyroid medication successfully. It walks through your diagnosis, cause, current labs and dose, and any past attempts to stop.
Do I Need T2? (Quiz)
T2 is the only over-the-counter thyroid hormone, but most patients have never heard of it. This 6-question quiz walks through your thyroid type, current medication, persistent symptoms, and metabolic status to determine whether direct T2 supplementation is a fit for your situation. No lab values needed.
Thyroid Supplement Quiz
Not sure which thyroid supplements are right for you? Answer 6 quick questions about your thyroid type, symptoms, goals, current medication, and recent labs, and this quiz matches you with a personalized 3-supplement stack built for your specific situation. It accounts for diagnosis-specific contraindications so you don’t end up taking the wrong thing for your condition.
Thyroid Aging Quiz
Is your thyroid making you look older than you are? This 10-question assessment walks through what you’re seeing in the mirror, from hair thinning and new wrinkles to brittle nails and facial puffiness, and scores how much thyroid-driven aging damage is showing up across your hair, skin, and nails. It then matches you with the specific products that target your damage pattern.
I’m building additional calculators, quizzes, and self-assessment tools to help you better understand your thyroid health. Check back regularly for new additions.
These tools are for informational and educational purposes only and are not a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider regarding your thyroid health.