If you are on nutritional supplements, feeds or a feeding tube, someone will ask at every appointment how much you have been managing. HydraCal is a simple way to answer that from a record rather than from memory.
It was written for head and neck cancer treatment, where swallowing is difficult and dehydration is one of the things your team is watching for. It works for anyone keeping track of fluid and calorie intake.
Download free on the App StoreFree. No account, no adverts, no subscriptions. iPhone and iPad.
What it does
Log in a couple of taps
Supplements, feeds, tube flushes and ordinary drinks. Built for days when you have no energy to spare for admin.
Your own products
Add whatever you have actually been prescribed, with the volume and calories from your own packaging.
Fluid targets or limits
Set the figure your team gave you as something to reach, or as a ceiling to stay under if you are fluid restricted.
A report for your team
Produce a dated record of your intake against your goals, ready to hand to a dietitian, nurse or doctor.
Everything stays on your phone
No accounts, no servers, nothing sent anywhere. The app makes no network connections at all.
Reminders, if you want them
Optional nudges to log your intake, on the days and at the times you choose.
My story
In 2025 I was diagnosed with throat and lymph node cancer. As part of that, I underwent radiotherapy and chemotherapy. Not nice. Eating and drinking became progressively harder.
My dietitian needed me to keep a written record of the liquid, food and calories I'd consumed each day, and to report back every week. Working in tech, I soon got bored of handwriting what I'd had. As I got more tired and my focus slipped, I would forget to make a note — and forget to bring the notes with me to the hospital.
It was at this point that I thought I needed a simple app to capture all this information, on a device I would always have with me. I created HydraCal, and after speaking with my dietitian I made some adjustments so that it would be of use to other people going through the same situation as I had.
Thankfully that stage of my life is behind me and I am well again. But if this app can help you in any way, then please use it. If you have any suggestions on how it could work better for you, please get in touch.
Dan
Important
HydraCal is a personal record-keeping tool. It is not a medical device and does not give medical, dietary or clinical advice. The targets it ships with are placeholder defaults, not recommendations — your fluid and calorie targets should be set by your dietitian, nurse or doctor, and you should follow their plan rather than the app's.
If you are unwell, struggling to keep fluids down, or worried about your intake, contact your healthcare team. The medical disclaimer has the detail.
Questions
Does it cost anything?
No, and there is nothing to buy inside it. There are no adverts and no subscription.
What happens to my data?
It stays on your device. HydraCal has no accounts and no servers, and contains no code that sends anything over the internet. You can export or back up your own data whenever you like, and it goes only where you send it. See the privacy policy.
Which products does it support?
Fortisip®, Calogen® and Vital 1.5 kcal are built in, and you can add any others yourself with the values from their packaging. HydraCal is not affiliated with or endorsed by any manufacturer.
Is there an Android version?
Not at the moment. It is an iPhone and iPad app.
How do I get in touch?
Use the contact form — for feedback, a problem, or to ask for a product to be added. It is a one-person project, so replies may not be instant, but every message is read.