VetruleEvery result shows its source
A clinical calculator for vet teams on iPhone and iPad, in 8 languages: English, Traditional Chinese, Japanese, Korean, Spanish, Portuguese, German and French.
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Coming soon to the App Store
- Formula
- RER = 70 × kg^0.75DER = RER × factor
- Source
- AAHA 2021 Nutrition and Weight Management Guidelines, Box 1
Printed under every result
One 4.5 kg cat, from calories to cans
1. How many calories a day
Enter the weight and pick a life stage. The factor comes from AAHA 2021, and the vet can change it.
260kcal/day
- RER
- 70 × 4.5^0.75 = 216.3 ≈ 216
- DER
- 216.3 × 1.2 (neutered adult) = 259.5 ≈ 260
2. Pick the prescription diet
143 Hill’s and Royal Canin cat and dog diets, using the calories each manufacturer publishes.
- a/d, canned
- 156 g a can
1173 kcal/kg
Manufacturer’s published kcal
3. Turn it into cans and grams
Daily calories become cans, split by meals. The source and the date it was checked sit under the result.
- k/d, canned
- 1½ cans a day (223 g)
¾ can a meal (111 g)
Hill’s Taiwan website
checked 2026-10-18
Fourteen calculators in 1.0
Each one names its basis and the year.
Every formula and source →| Calculator | What it does | Based on |
|---|---|---|
| Energy requirement | RER and DER with life-stage factors | AAHA 2021 |
| Prescription diet | Daily kcal into cans or grams, split by meals | Manufacturers’ published kcal |
| Fluids and drip rate | Maintenance, deficit and losses as mL/hr and drops per minute | AAHA 2024 |
| Single dose | The ordered dose into mL to draw up | The vet’s order |
| CRI: syringe, undiluted, fluid bag | Syringe mix, undiluted pump rate, or drug added to a fluid bag | Grubb, IVAPM 2023 |
| Unit conversion | Common clinical units | Unit definitions |
| Transfusion volume | Volume to reach the ordered PCV | Merck 2024; Short 2012 |
| Body surface area (BSA) | BSA in m², and mg/m² orders into mg | Merck; Girens 2019 |
| Potassium supplementation | mL of KCl for a target bag concentration, with the delivered mEq/kg/hr | AAHA 2024 |
| Dilution | C1 × V1 = C2 × V2 | Pharm J 2025 |
| Shock bolus volume | Ordered mL/kg into total, per-bolus volume and pump rate | AAHA 2024; AAHA/AAFP 2013 |
| Serum osmolality (calculated) | Calculated serum osmolality and osmolal gap | Dugger 2014 |
| Cat age | Human-equivalent age and life stage | AAFP–AAHA 2010; 2021 |
| Due date | Whelping or queening window from a reference date | Merck 2025 |
Vetrule converts the vet’s order. It never suggests a dose.
The vet enters the dose and makes the clinical call.
Offline, and nothing leaves the phone
- Weight entered once
- Species and weight go in the patient bar once. Every calculator uses them, and the bar shows how long ago the weight was entered.
- Fully offline
- Calculations need no network. Everything runs on the phone.
- Collects no data
- No account and no analytics. Patient names and weights stay on the device.
- No result until inputs are valid
- Every field has to check out first.
- Report a result
- A number looks wrong? Tap “Report this result” to email us.
We’ll write back at launch
Vetrule is built by someone who works at a vet clinic in Taiwan.
Email hello@vetrule.com