01 · The number goes stale
Static calculator
5.0 mg/mL · 10.0 units
Vial 10 mg → 5 mg
VialMath recomputes
2.5 mg/mL · 20.0 units
Protocol calculator + tracker
Change one thing.
Everything updates.
A free calculator gives you one number — then the schedule moves, and it's stale. VialMath keeps the whole protocol coherent: draw volume, what's due today, which vial runs out first and when to reorder, recomputed the moment any input changes. It computes. It never tells you what to do.
Free tier: two tracked compounds. Orals added on the Orals screen don't count. No card, no account, no trial clock.
Vials — sample protocol
ON TRACK
Compound A
daily · 10 mg in 2 mL
Concentration
5.0 mg/mL
Draw volume
10.0 units
Doses remaining
14
Runs out
in 13 days
Reorder by
in 6 days
Dose 500 mcg
Change the dose — every number above recomputes · example data
How it works
One protocol. Change any input. Watch the rest stay honest.
A sample protocol on example data — Compound A daily, Compound B on a 5-on / 2-off cycle; labels, never a real one. Move the dose, change the vial, or mark yesterday skipped, and watch draw volume, doses remaining, run-out and reorder-by recompute together.
1 · Enter
Your numbers
Compound A
daily · 2 mL water · 7-day lead time
Compound B
250 mcg · 5 mg in 2 mL · 5-on / 2-off
2 · Calculate
Reconstitution
5.0 mg/mL · draw 10.0 units
Compound A
Concentration5.0 mg/mL
Draw volume10.0 units
U-100 syringe: 100 units = 1 mL. Draw = dose ÷ concentration × 100.
3 · Schedule
Today
A due 10.0 units · B day 3 of 5 on
Compound A · due500 mcg 10.0 units
Compound B · due250 mcg 10.0 units
B cycleday 3 of 5 on
4 · Track
Vials
7.0 mg left · 14 doses
Compound A
Used3.0 mg
Left7.0 mg
Doses left14
Yesterday's dose
B · doses left18
5 · Forecast
Run-out and reorder
runs out in 13 days · reorder in 6 days ON TRACK
Compound A
ON TRACK
Runs outin 13 days
Reorder byin 6 days
Compound B
Runs outin 23 days
Reorder byin 16 days
Example data · Compound A / B are labels, not substances · reorder-by = run-out minus your lead time · dates are shown when you open the app — VialMath sends no alerts
Start free — no signup
The same arithmetic runs on your own numbers, on your own device.
Built to be checked, not trusted blindly
Your protocol isn't our data.
Nothing here asks you to take our word for it. Other tools interpret and advise; VialMath only calculates — and you can check every claim below yourself.
01
Check it yourself.
Open your browser's network panel and use the app. Beyond loading its own files, VialMath makes exactly two
kinds of request, and neither carries your protocol: a check of its own version.json (carries none
of your data — no key, nothing you entered), and — only when you activate Power — one license check, sent
straight to Gumroad, that carries your key and nothing else about you.
Step-by-step walkthrough →
02
No account, no cloud, no analytics in the app.
There is no login and no signup. Every calculation runs on your device, and the app runs no analytics. Your protocol data never leaves your device.
03
No database, no recommendations.
Zero built-in compounds. You name everything. VialMath never suggests a compound, a dose, or a range, and never reacts to what's in a blend. That boundary is permanent.
04
Export your protocol, always — and it's your backup.
A full JSON backup or an .ics calendar of your doses and reorder dates — free, one tap, any time. Local-first also means you own the backup: nothing is on our servers, so nothing can restore a lost device. Once more than 20 entries are logged, Today reminds you when your last backup is 14 or more days old, or there isn't one.
Independent verification
6783
browser checks
Run the exact suite that gated this build, live in your browser.
We fix what breaks, and we say so. If something's wrong, tell us what you did and what you expected — [email protected].
Why not a calculator, or a spreadsheet
A free calculator gives you the first number. Then the schedule moves.
02 · The count drifts
Static spreadsheet
7.0 mg left · 14 doses
Yesterday → skipped
VialMath recomputes
7.5 mg left · 15 doses
03 · You find out late
Static sheet
Run-out ? · reorder ?
Lead time · 7 days
VialMath forecast
Runs out in 13 days · reorder in 6 days
What's in the app
Six surfaces, one coherent state.
All examples use "Compound A" / "Compound B". VialMath never ships or suggests a real compound, dose, or range. Tap a surface to see it.
TodayWhat's due, computed for the exact calendar day — injectables and orals in one list.
Each line carries that day's dose and draw volume; log it done or skipped and every dependent number moves.
Compound A500 mcg · 10.0 units
Compound B250 mcg · 10.0 units
Oral A1 capsule
Today — example data
VialsReconstitution math from your own vial size and water, with draw volume in U-100 syringe units.
Enter vial size and water once; concentration, draw, used and left are computed from that entry and your log.
Compound A
Concentration5.0 mg/mL
Draw volume10.0 units
Doses remaining14
Vials — example data
Forecast + ReorderA burn-rate run-out date and a reorder-by date built from your lead time.
Run-out walks your actual schedule, off-days included; reorder-by is run-out minus your lead time. Both wait in Today when you open the app — VialMath sends no alerts.
Runs outin 13 days
Reorder byin 6 days
Forecast — example data
Gate decisionsSet a date and a question; log what you decided. A permanent decision log.
Continue, adjust, or stop: VialMath records that you decided, and when. It never evaluates the decision.
Due Sep 01GATE CHECK
"Continue to Phase 2?"
Gates — example data
BlendsGroup compounds you already entered and log one dose for the group. Local and private.
A blend is only a name you gave to compounds you already entered — never shared, never surfaced as "popular", never checked for combinations. The vial math counts every component that leaves the vial.
"Blend 1"
Compound A + Compound B
Blends — example data
Metrics + OralsA daily metric log with a 7-day average, plus your oral stack in the same place. Orals added on the Orals screen are free and don't count toward the limit.
Capsules, grams, IU — whatever the label says — sit beside your injectables in Today. The metric log keeps a 7-day average and all-time low/high; CSV import brings an existing log in after you confirm a preview.
7-day average197.0
All-time low188.0
Metrics — example data
Ready when you are
Start free. $39 once for the rest.
Free tracks up to 2 compounds — orals added on the Orals screen are free, no matter how many. Power removes the limit. $39 once. No subscription. No account.
VialMath Free
The whole calculator, and up to 2 compounds.
Free. No credit card. No account.
- The full reconstitution calculator — and the equation behind every number
- Up to 2 tracked compounds (ended ones don't count; orals on the Orals screen don't count)
- A schedule for each, a Today view, and your full history
- Vial tracking and your run-out date
- Forecasting, calendar export (.ics), CSV import
- Backup and export, any time
Full-capability mode
VialMath Power
Everything you run — and the physical vials behind it.
$39ONCE
Unlock Power — $39 onceYou can request a refund within 30 days of purchase — how it works.
Tracked compoundsA · B · C · D +
Doses per day · D2× daily
Cycle windows · CCycle 1 done · Cycle 2, day 3
Data check2 entries side by side · 1 differs
Vial 1 · openheld 16 days · 2.0 mg left · 4 doses
Vial 2 · sealedopen next · 10 mg · 20 doses
Vial inventory · 7-day leadVial 1 runs out in 3 days · Vial 2 in 23 · reorder in 16
Dose-log exportEvery entry with its arithmetic · .csv
- More than two tracked compounds — the 2-compound limit lifted
- Multiple doses per day, on their own schedules
- Cycle windows — dated blocks with breaks between them (Cycle 1, a break, Cycle 2); a repeating N-on / M-off schedule is free
- Vial inventory — a vial-by-vial ledger: which physical vial to open next, and how long each has been held
- Applying a scenario as a dated dose change — entering a different dose in “What if I changed the dose?” to see what changes is free; with Power you can save it as a dose change from today
- Data check — puts two numbers you entered side by side wherever they stopped agreeing. A logged entry it lists for you to delete or keep is shown on Free too
- Dose log export — every dose, with the arithmetic beside it (.csv)
Every tracker models the protocol. Power models the physical vials.
How activation works
Pay once — checkout runs on Gumroad. Your key is on the receipt page and in your email; paste it in under Settings, on the license key button. One key covers your phone and your laptop, and everything you already entered carries over untouched — activating Power only adds capability.
Never gated — on Free or Power:
full backupcalendar exportyour historyyour privacy
The arithmetic is always correct and the equation is always shown — on Free and on Power alike. Power means more capable. It never means more trustworthy.
Questions
FAQ
Will I lose my data if I switch phones or clear my browser?
VialMath stores everything locally on the device you're using — that's the same design choice that keeps your protocol data private, and it means there is no cloud copy to restore from. Export a backup (JSON) before you switch devices or clear site data, then import it on the new one. Once more than 20 entries are logged, Today reminds you when your last backup is 14 or more days old, or there isn't one. If you have Power, your key is not in the backup file: keep it from your Gumroad receipt and enter it once in Settings on the new device.
What exactly do I get for $39?
VialMath Power unlocks what the app's own Power sheet lists: more than two tracked compounds · multiple doses per day, on their own schedules · cycle windows · vial inventory · applying a scenario as a dated dose change (the “What if I changed the dose?” preview is free; saving it as a dose change is Power) · data check (a logged entry it lists for you to delete or keep is shown on Free too) · dose log export. The calculator, forecasting, calendar export, backup and export, and CSV import are free.
Can I try Power before buying?
Not on your own data: Free doesn't run the Power features, and there's no Power trial. The example the app opens with on a first visit shows a few of them. VialMath Free costs nothing, requires no account and no payment details, and is not a trial — it does not expire. If you buy Power and it isn't useful to you, you can request a refund within 30 days of purchase.
I already track two compounds and want to add a third. What happens?
Adding a third opens a sheet that says it's part of VialMath Power and, in the app's own words: “You can keep going without it — nothing you have entered changes, and nothing is removed.” The third isn't added unless Power is active; your two stay exactly as they are. If you pay for Power, nothing you have entered changes, and nothing is removed. Ended compounds don't count toward the two. Orals added on the Orals screen don't count at all; an oral saved as a compound (the "No — pre-mixed or oral" answer when adding a compound) currently does.
Can I use one key on two devices?
Yes. One key covers your phone and your laptop; on each one, paste it in from Settings, on the license key button. If you pay for Power, nothing you have entered changes, and nothing is removed. Your data does not sync between your devices — VialMath is local-first, so each device keeps its own copy. To move a protocol, export a backup on one device and import it on the other; import replaces everything currently in the app after one confirmation. Your license key is not for resale, sharing, or redistribution.
Will I be charged again for Power?
No. Power is $39, once: there is no subscription, no recurring charge, and no feature moved behind a higher tier after your purchase. Everything unlocked at purchase is yours for good, Power never loses a feature, and nothing will ever be sold above Power.
Do you offer refunds?
Yes. If VialMath isn't useful to you, you can request a refund within 30 days of purchase: email [email protected] and we'll process it through the payment processor that handled your purchase. The terms of sale set out the full policy.
Does VialMath tell me if my dose or protocol is safe?
No. It computes — it never evaluates. There's no color-coded "safe/unsafe", no reference ranges, no combination or interaction warnings, ever. For anything medical, talk to the clinician who prescribes or oversees your protocol.
Does the app phone home?
Beyond loading its own files, it makes two kinds of request. A one-time license check at activation sends
your license key straight from your browser to Gumroad — never protocol data — so it never reaches us, and
we have no IP address from it to keep. And it fetches its own
version.json when it opens or returns to the foreground, so it can tell you a newer build exists;
that carries no key, no identifier and no protocol data. Everything else runs locally.
See how to check this yourself →
How does activating Power work?
Pay once on Gumroad. Your key is on the receipt page and in your email; paste it in under Settings, on the license key button. One key covers your phone and your laptop, everything you already entered carries over untouched, and after that one check the app runs without a connection.
What happens if I forget to log a dose?
Pick the date from History and log it after the fact — done, skipped, or edited. A late log still counts; VialMath never treats a retroactive entry as a missed one.
Can I import my existing log from a spreadsheet?
Yes. The Data view has a CSV import for both your metric log and your dose history. You map which column is which, toggle whether the first row is a header, and review a preview — nothing commits until you confirm it.
Why isn't there a built-in compound or dosing database?
By design, not as a missing feature. VialMath computes arithmetic and schedules from the numbers you enter — it doesn't supply, suggest, rank, or evaluate any compound, dose, or range. That boundary is permanent.
Will blends warn me about combining things, or flag "commonly stacked" groups?
No, and this is permanent, not a roadmap item. A blend is only a name you gave to compounds you already entered — VialMath never checks combinations, never warns about interactions, and never surfaces what other people group together.
Is this a native app? Does it work offline?
VialMath is a web app you install like a native one (a PWA) — add it to your home screen from any modern mobile or desktop browser, or just keep it open as a tab. After the one-time license check at activation, it runs without needing a connection. All storage is local.
You already have the numbers. Keep them coherent.
Power is $39, once. No subscription. No account. Everything you already entered carries over untouched — activating Power only adds capability.
Free tools
One question each. No signup, nothing to install.
Reconstitution calculator
Vial size, water added, target dose → concentration and draw volume in U-100 units.
How long will a vial last?
Vial size, dose and interval → doses per vial and days per vial.
When does a vial run out?
What's left, dose and interval → a run-out date, and a reorder-by date if you add lead time.
All free tools and reads →