Dog Pregnancy Calculator

Q: What if I do not know the exact mating date?

Use your best guess and tick Dog was mated on multiple days . Enter the earliest and latest possible dates. The tool widens the window so it still covers the real due date. Ask your vet for an ultrasound to check how far along she is.

Updated Aug 28, 2026 By Jehan Wadia

Introduction

Dogs are pregnant for about 63 days, or roughly nine weeks. That is a short time to get ready. This dog pregnancy calculator tells you when your dog will most likely have her puppies, based on the date she was bred.

Just enter the mating date, or the ovulation or LH surge date if your vet ran blood tests. Then pick your dog's size and breed. The calculator gives you a due date, a whelping window, and a full week-by-week timeline of what is happening inside your dog and what you should do.

You also get key dates for vet visits, like when to book an ultrasound (day 25–28) and when an X-ray can count the puppies (day 45 or later). Small dogs often give birth a bit early. Giant breeds may go a bit late. Flat-faced breeds like Bulldogs and Pugs often need a C-section, so the tool flags that too.

This calculator is a planning tool, not a vet. Always work with your veterinarian during your dog's pregnancy, and call right away if labor starts late or something seems wrong. Once the puppies arrive, our Puppy Weight Calculator and Dog Food Calculator can help you track their growth and feed the nursing mother properly.

How to use our Dog Pregnancy Calculator

Enter your dog's breeding date and a few details about her. The calculator gives you her due date, a whelping window, her current day of pregnancy, a week-by-week timeline, and key vet dates.

Reference Date Type: Pick the date you know. Choose "Mating / Breeding Date" if you only know when she was bred. Choose "Ovulation Date" or "LH Surge Date" if your vet did blood tests. Lab dates give a more exact due date. (For humans, the same idea is used by our Ovulation Calculator.)

Dog was mated on multiple days: Tick this box if she was bred more than once. Then enter the first and last mating dates. The due date window will be made wider to cover all of those days.

Date of Mating: Enter the day the breeding happened. This is the main date used to count her 63 days of pregnancy. If you want to count the days by hand, the Date Duration Calculator and Days Until Calculator are handy backups.

Dog Size: Choose the size that fits your dog: Toy, Small, Medium, Large, or Giant. Small dogs often whelp a bit early, and giant breeds often go a bit late, so this shifts the due date.

Weight Units: Pick pounds or kilograms. This only changes how the weight ranges are shown next to each size. Need a quick swap on your own scale readings? Use the Pounds to Kilograms Calculator or the Kg to Lbs Calculator.

Temperature Units: Pick Fahrenheit or Celsius. This sets how the pre-labour temperature drop is shown in the Week 9 tips. You can also convert readings with the Fahrenheit to Celsius Calculator.

Breed: Start typing her breed and pick it from the list. This is optional, but it sets her size for you and flags risks like C-section needs or big litters.

Number of Previous Pregnancies: Enter 0 if this is her first litter. First-time moms get extra watch-closely tips near her due date.

Known Health Conditions: Type any health problems she has, like a past C-section or thyroid issues. This is optional and adds a reminder to get extra vet care.

Click Calculate Pregnancy Timeline to see your results, or Reset to start over.

Dog Pregnancy: What You Need to Know

A dog's pregnancy is short. Most dogs give birth about 63 days (roughly 9 weeks) after they get pregnant. Giving birth is called whelping. Because the time is so short, every week brings big changes, and a few days of planning can make a large difference for the mother and her puppies. By comparison, a human pregnancy runs about 40 weeks (see our Due Date Calculator), and a cow carries her calf for about 283 days (see the Cow Gestation Calculator).

Why Due Dates Are Only Estimates

The day a dog mates is not always the day she gets pregnant. Sperm can live inside her for up to a week, so puppies may start growing days after breeding. That is why a due date based on a mating date can be off by about 5 days. The same uncertainty affects human dating, which is why tools like the Conception Calculator also give a range rather than a single day.

Vets get a much closer date using blood tests:

Ovulation date (found with progesterone testing) — birth comes about 63 days later, give or take a day.
LH surge date — birth comes about 65 days later, give or take a day.

These lab dates are the most accurate way to know when puppies will arrive.

Dog Size and Breed Change the Timing

Small and toy dogs often whelp a day or two early. Giant breeds may go a day or two late. Some breeds also need extra care. Flat-faced (brachycephalic) breeds like French Bulldogs, Pugs and English Bulldogs have big puppy heads and narrow hips, so many need a planned C-section. Giant breeds often have 8 to 12 or more puppies and can be in labor for many hours.

The 9 Weeks in Short

Weeks 1–3: Eggs are fertilized and embryos attach to the womb. She looks normal, but may act clingy or eat less.
Weeks 4–5: Heartbeats can be seen on ultrasound from about day 25. Her belly starts to thicken.
Weeks 6–7: Puppies grow fast and bones harden. An X-ray from day 45 can count the puppies. Switch her to puppy food for extra calories — the Dog Calorie Calculator can help you work out how much more she needs.
Weeks 8–9: Set up the whelping box, check her temperature twice a day, and stay close.

If you like tracking progress in weeks rather than days, the Weeks Calculator makes it easy to see exactly how far along she is.

Signs Labor Is Close

A dog's normal temperature is about 101–102.5 °F (38.3–39.2 °C). When it drops below 99 °F (37.2 °C), labor usually starts within 24 hours. Other signs are nesting, panting, restlessness, and refusing food. Use the Celsius to Fahrenheit Calculator if your thermometer reads in the other scale.

When to Call Your Vet

No puppies by day 65–68.
Strong pushing for more than 30 minutes with no puppy.
More than 2 hours between puppies while she still has more inside.
Green, black or bloody discharge before the first puppy is born.
She seems weak, shaky, or very sick.

First-time mothers, dogs with health problems, and dogs that had a C-section before need closer watching. Always plan ahead and keep an emergency vet number handy before the due date arrives.

Related Pet Tools

Puppy Weight Calculator — estimate how big each puppy will grow.
Dog Food Calculator — portion sizes for a pregnant or nursing female.
Dog Age Calculator — convert your dog's age into human years.
Chocolate Toxicity Calculator — check emergency risk if she eats chocolate.
Cat Age Calculator — the same idea for feline family members.

Formulas used

Reference date midpoint (multiple mating dates)

D_{\text{ref}} = D_{\text{start}} + \left\lfloor \frac{D_{\text{end}} - D_{\text{start}}}{2} \right\rfloor

Total gestation length

G_{\text{total}} = G_{\text{base}} + \Delta_{\text{size}} + \Delta_{\text{breed}}

Most likely whelping (due) date

D_{\text{due}} = D_{\text{ref}} + G_{\text{total}}

Whelping window (earliest and latest dates)

D_{\text{win,start}} = D_{\text{start}} + W_{\min}, \qquad D_{\text{win,end}} = D_{\text{end}} + W_{\max}

Due date clamped into the whelping window

D_{\text{due}} = \min\left(\max\left(D_{\text{due}},\, D_{\text{win,start}}\right),\, D_{\text{win,end}}\right)

Current gestation day and pregnancy week

d_{\text{cur}} = D_{\text{today}} - D_{\text{ref}}, \qquad W_{\text{cur}} = \min\left(9,\ \max\left(1,\ \left\lceil \frac{d_{\text{cur}}}{7} \right\rceil\right)\right)

Days remaining until whelping and percent complete

N_{\text{days}} = D_{\text{due}} - D_{\text{today}}, \qquad P = \frac{d_{\text{cur}}}{G_{\text{total}}} \times 100\%

Unit conversions (weight and temperature)

m_{\text{kg}} = m_{\text{lb}} \times 0.453592, \qquad T_{^\circ C} = \left(T_{^\circ F} - 32\right) \times \frac{5}{9}

Frequently asked questions

Is this dog pregnancy calculator free to use?

Yes. The dog pregnancy calculator is free and you do not need to sign up. Enter the breeding date, click Calculate Pregnancy Timeline, and you get the due date, whelping window, and week-by-week plan right away.

Can this tool tell me if my dog is actually pregnant?

No. It only counts forward from a breeding date. To confirm pregnancy, your vet can do an ultrasound from about day 25, a blood relaxin test from about day 21–25, or an X-ray from day 45.

What does the whelping window mean?

It is the range of days when puppies are most likely to arrive. The first date is when you should have everything ready. The last date is when you should call your vet if no puppies have come. Birth on any day inside this window is normal.

What if I do not know the exact mating date?

Use your best guess and tick Dog was mated on multiple days. Enter the earliest and latest possible dates. The tool widens the window so it still covers the real due date. Ask your vet for an ultrasound to check how far along she is.

Why does the due date change when I pick a different dog size?

Size changes the count. Toy and small dogs get 2 days taken off, medium and large dogs stay at 63 days, and giant dogs get 2 days added. Smaller dogs usually whelp a little early and giant breeds often run late.

Why does picking a breed change my results?

Choosing a breed sets the size tier for you and adds a small day shift for some breeds. It also turns on warnings, like C-section risk for flat-faced breeds or large-litter planning for giant breeds.

My breed is not on the list. Does that matter?

Not much. The tool tells you that no breed shift was used, but the size tier you picked still adjusts the date. Just choose the size that best matches your dog's weight.

Why does the LH surge date add 65 days instead of 63?

Ovulation happens about 2 days after the LH surge. Puppies are counted from ovulation, so the LH date needs 2 extra days. Both lab dates are accurate to about 1 day.

Is it safe if my dog gives birth on day 58?

It can be. Puppies born from day 58 counted from mating are often fine, because the real conception day may be later than the mating day. Puppies born before day 58 from ovulation are usually too early and need a vet right away.

What should I do if my dog passes her due date?

Stay calm and watch her. If there is no labor by the last date in your whelping window (about day 65–68), call your vet the same day. Waiting too long can put the puppies at risk.

How many puppies will my dog have?

This tool does not guess litter size. Small dogs often have 1–4 puppies, medium dogs 4–6, and large or giant breeds 8–12 or more. An X-ray from day 45 gives an accurate count so you know when whelping is done.

Why does the tool ask about previous pregnancies?

First-time (maiden) mothers often need more help. If you enter 0, the tool adds close-watch tips from day 50 and during weeks 8 and 9. Experienced mothers get standard monitoring notes.

Why do I need to enter health conditions?

It is optional, but if you list things like a past C-section, thyroid problems, or heart disease, the tool adds reminders to arrange extra vet checks in the last weeks. The text stays in your browser only.

When should I set up the whelping box?

Around day 50. Your key dates table shows the exact date. Put it in a quiet, warm, draft-free spot and let her sleep in it before labor, so she does not pick a closet or your bed instead.

When do I start taking her temperature?

Start twice-daily rectal checks around day 55. Write down each reading so you know her normal. A drop below 99 °F (37.2 °C) usually means labor within 24 hours.

How long does whelping take?

Most dogs finish in 6 to 12 hours. Giant breeds with big litters can take 12 to 24 hours. Puppies usually come every 30 to 60 minutes. Call your vet if she pushes hard for 30 minutes with no puppy, or rests over 2 hours with puppies still inside.

Can I still walk and exercise my pregnant dog?

Yes, gentle daily walks are good for her. Cut out rough play, jumping, and long runs from about week 5. In the last two weeks, keep walks short and close to home.

When should I switch her food?

Around day 35–40, shown in your key dates table. Move her to a high-quality puppy or performance food and feed smaller meals more often, since her belly gets crowded. Her calorie needs rise the most in the last three weeks.

Does the calculator save my dog's details?

No. Everything runs in your browser and nothing is sent or stored. If you reload the page, you will need to enter the dates again, so write down or print your key dates.

Why does my current day of pregnancy look off by a day or two?

When you enter more than one mating date, the tool counts from the middle date of that range. It also compares your dates to today, so the day number moves forward each morning.

Does the calculator work for a planned C-section?

It gives you the dates to plan around, but your vet sets the surgery day. For flat-faced and high-risk breeds, the tool flags a date about a week before the due date to book that talk. Vets often use progesterone tests to pick the safest day.

Can I use this calculator for a mixed-breed dog?

Yes. Leave the breed box blank and just pick the size tier that matches her adult weight. If she has a flat face or a very wide-headed father, ask your vet about extra birth risk.

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