Calculator directory

Start with the job you actually need to do. Each calculator combines the working formula with context on when the answer is a useful estimate and when it is time to involve your vet.

Dog Age Calculator

Translate dog years into a human-age estimate using size bands rather than the outdated “multiply by seven” shortcut.

Small to giant breeds Life-stage guidance

Puppy Growth Calculator

Estimate adult weight from current age, current weight and expected size class, then sanity-check it against growth trends.

Growth-stage notes Weight range output

Dog Pregnancy Calculator

Map a mating date to the average due date, expected window and milestone timeline for late-pregnancy planning.

63-day baseline Whelping prep cues

Cat Age Calculator

Convert cat years to a human-age estimate using the first-year, second-year and later-life stages recognised in cat welfare guidance.

Life-stage mapping Senior-care context

Raw Dog Food Calculator

Estimate a daily raw portion and simple 80/10/10 split, then cross-check it against hygiene, safety and nutritional advice.

Portion estimate Safety reminders

How to use the numbers well

A good calculator does not pretend to be a diagnosis. PetCalc is built to help you prepare, compare and ask sharper questions.

Use trends, not single readings. Weight, appetite and behaviour over time usually matter more than one isolated number.
Match the estimate to the pet in front of you. Breed size, body condition, litter size and age stage can all change how useful an estimate is.
Escalate quickly when the stakes are high. Pregnancy concerns, poor growth, unexplained weight loss or sudden behaviour changes need veterinary input.

What makes PetCalc different

  • No “coming soon” dead ends. Every calculator linked here is live and indexable.
  • Clean route structure, proper canonicals, JSON-LD and crawl-friendly internal linking.
  • Answers written for UK owners, with direct source links to veterinary, welfare or government guidance.
  • Maths kept separate from advice, so the result is quick to use and easier to sanity-check.
🐾 From the team behind PetCalc

This one's partly your fault — thank you.

PetCalc is built by the same small UK team that made GardenCalc. Honestly, it exists because of you — the folks who used our garden tools, emailed us what was missing, and kept coming back. That gave us the nerve to build something for our pets too.

Everything here is free, and staying that way. No paywalls, no locked “pro” version, no selling your data. Just accurate tools, plain-English guidance, and as much genuinely useful help as we can give — made with a bit of love.

If you’ve got a pet, the questions never really stop. So we want to hear what you’re stuck on — because the next calculator we build will most likely be one you asked for.

Join & tell us what to build next ↓

Frequently asked questions

Can a calculator replace a veterinary appointment?
No. Use calculators for planning and rough comparison, not for diagnosis. PDSA recommends regular home checks and contacting your vet if you notice anything worrying or out of character. Source: PDSA, “How to give your pet a health check at home”
Do dogs and cats age in the same way?
No. AVMA notes that dogs do not age at a flat seven-to-one rate, and cat welfare guidance from International Cat Care uses different life stages altogether. Species and size both matter. Sources: AVMA, “Senior pets”; International Cat Care, “How to tell your cat’s age in human years”
How often should I check my pet’s weight or body condition?
Regularly enough to spot change early. PDSA advises routine nose-to-tail home checks and body-condition scoring, because shape and trend often reveal trouble before one-off numbers do. Sources: PDSA health checks; PDSA dog body-condition score
Are microchips legally required in the UK?
Dogs must be microchipped across the UK, and in England pet cats must also be microchipped and registered by 20 weeks old. If you move or change phone number, keep the database details current. Source: GOV.UK, “Get your dog or cat microchipped”
Can raw feeding carry hygiene or safety risks?
Yes. The Food Standards Agency warns that raw pet food can carry harmful bacteria, and BSAVA notes higher Salmonella and resistant E. coli findings in UK dogs fed raw meat diets in the cited research summary. Sources: Food Standards Agency, “Raw pet food”; BSAVA PetSavers, “Raw meat diets”
How should I use a puppy growth prediction?
Treat it as a planning estimate, then compare your puppy’s growth pattern with recognised charts and vet advice. The Kennel Club points owners toward WALTHAM growth charts for tracking and predicted adult weight. Sources: The Kennel Club, “Puppy nutrition”; WALTHAM Petcare Science Institute, “Puppy Growth Charts”