How old is your pet, really?
28 free calculators, all on real veterinary sources (NRC, WSAVA, AAHA). Try one now — your dog's real age in human years in five seconds.
Want to log weight, vet visits, and meds over time? Create a free account →
- Small · <20 lb
- Medium · 20–50 lb
- Large · 50–90 lb
- Giant · 90+ lb
Got a cat? Try the cat age calculator →
All 28 calculators & guides
Free, neutral, evidence-based. Built by one person · Methodology never tilted by sponsor money.
Compare a dog and a cat
The viral one. Is your cat older than your dog in human terms?
OpenDog age calculator
Real dog years to human years, AKC method, breed-aware.
OpenCat age calculator
Cat years to human years, indoor vs outdoor lifespan adjusted.
OpenChocolate toxicity (dogs)
My dog ate chocolate — how dangerous? Vet-referenced severity bands + hotline numbers.
Grape toxicity (dogs)
Acute kidney injury risk. Any ingestion warrants a hotline call.
Raisin toxicity (dogs)
Concentrated-grape dose math + severity bands.
Xylitol toxicity (dogs)
Sugar-free gum + peanut-butter exposures. Fastest-acting common toxin.
Dog pregnancy / gestation
63-day timeline with prenatal milestones.
Dog poop color guide
Interactive: pick color + consistency, see vet urgency.
Daily calorie needs (dogs)
NRC-based RER × MER. Life-stage, activity, and neuter-adjusted.
Calorie deficit (weight loss)
Daily target for a safe, sustainable weight-loss plan.
Raw food amount
PMR / BARF daily grams, with muscle / organ / bone breakdown.
Puppy growth
How big will my puppy get? Size-band growth curves + milestones.
Crate size guide
Right crate size by adult weight + optional body measurements.
Compare two dogs
Side-by-side human ages, life stages, and a plain-English summary.
Daily calorie needs (cats)
Cat-tuned multipliers + a safer weight-loss plan (hepatic lipidosis aware).
Cat pregnancy / gestation
62-day queen timeline with prenatal milestones + eclampsia signs.
Litter box count (cats)
The 1.5× rule: how many boxes for your household + where to put them.
Cat litter cost
Estimate monthly + annual litter spend across litter types.
Ideal weight (dog & cat)
Visual BCS picker back-calculates the target weight and time to reach it.
Senior pet wellness tracker
Log weight + appetite + mobility over time. Stored in your browser only.
Food safety — can pets eat this?
Searchable safe / caution / toxic list for 50+ human foods.
Flea & tick prevention guide
Collar vs topical vs oral — honest trade-offs and FDA adverse-event data.
Dewormer guide
Which worm, which drug. OTC vs prescription, puppy/kitten schedule.
Wet vs dry food split
How much wet + dry per day for a target mix and calorie target.
Treat allowance
The AAHA 10% rule with a database of common treats and what fits.
Water intake
Daily water needs split into "from food" vs "from the bowl".
Lifetime cost of ownership
Food + vet + grooming + supplies + insurance over a full lifespan.
No calculators match that species yet. .
Dog ages at a glance
Same chronological age, very different human-equivalent age — that's the AKC size-based method in action.
Daily calorie needs — adult dog, neutered
NRC 2006 method (RER × 1.6 MER). Adjust for activity, age, breed in the full calculator.
| Body weight | Sedentary / indoor | Active adult | Working / athletic |
|---|---|---|---|
| 5 lb (2.3 kg) | 156 kcal | 208 kcal | 260 kcal |
| 15 lb (6.8 kg) | 354 kcal | 472 kcal | 590 kcal |
| 30 lb (13.6 kg) | 595 kcal | 794 kcal | 992 kcal |
| 50 lb (22.7 kg) | 875 kcal | 1166 kcal | 1458 kcal |
| 75 lb (34.0 kg) | 1182 kcal | 1576 kcal | 1970 kcal |
| 100 lb (45.4 kg) | 1470 kcal | 1960 kcal | 2450 kcal |
Numbers are kcal per day for a neutered adult dog. Multiply by 1.6 for unneutered intact dogs, by 2.0 for puppies up to 4 months, by 0.8 for senior (10+) dogs. Underlying formula: RER = 70 × (kg0.75), then MER = RER × multiplier.
Made by Carl and Mochi
Hi, I'm Carl. Goodboy Atlas started because every time I tried to answer a simple numerical question about Mochi — a mixed-breed rescue — I'd land on either a food-brand calculator quietly pushing kibble, a generic listicle with no sources, or a 2019 Reddit thread written by someone with no veterinary background.
So I built the site I wished existed: every calculator shows its method, cites a real source, and the recommendations aren't biased by sponsor money. This site is ad-supported — that's what keeps it free for everyone. If you'd rather support Goodboy Atlas directly, the Buy Me a Coffee link in the footer goes to me, not a company. No accounts, no AI-generated filler. Just the math, the sources, and a real human (and Mochi) behind it.
Why we built this
Pet calculators online are usually either branded marketing tools (designed to funnel you toward a specific food brand) or buried single-purpose pages on huge general sites. We wanted one neutral place that does the math carefully and explains where each number comes from.
Every calculator on Goodboy Atlas shows two things on the same page: the result, and the method we used to get there. If you disagree with our assumptions, change them. If you want to read the underlying source, the citations are at the bottom of every page.
We're starting with the dog age calculator because it's the most commonly searched and most commonly mangled. Over the next few months we'll add feeding, exercise, lifetime cost, and cat-specific tools. Subscribe for a heads-up when each launches.