Dog Benadryl Dosage Calculator

Use our Benadryl dosage for dogs calculator to estimate diphenhydramine dose from your dog’s weight. Get dosage in mg, plus liquid (12.5 mg / 5 mL), 25 mg tablets, and 12.5 mg chewables. Includes a dosing-by-weight chart and how often Benadryl is typically given.

Your dog's weight (lb)
Enter your dog's weight in pounds (lb).
Results
Dosage by weight (mg)
Common rule of thumb: 1 mg per lb of body weight (confirm with your vet).
Liquid (12.5 mg / 5 mL) (mL)
Converts mg dose into mL using 2.5 mg per mL.
Tablets (x 25 mg)
Number of 25 mg tablets needed to reach the mg dose.
Chewable tablets (x 12.5 mg)
Number of 12.5 mg chewables needed to reach the mg dose.
Estimate only. Confirm diphenhydramine dosing and product type with your veterinarian.
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What Is Benadryl for Dogs?

Benadryl is a common brand name for diphenhydramine, an antihistamine that veterinarians may use for allergic reactions and itching in dogs. :contentReference[oaicite:0]{index=0}

Dosing depends on your dog’s weight and individual factors (age, other conditions, and other medications). Many sources reference veterinary guidance in the 2–4 mg/kg range given every 8–12 hours, which is roughly 0.9–1.8 mg per pound. :contentReference[oaicite:1]{index=1}

This calculator provides an estimate based on weight and then converts that dose into common forms: liquid (12.5 mg / 5 mL), 25 mg tablets, and 12.5 mg chewable tablets.

Benadryl Dosage Formula

A common rule-of-thumb is about 1 mg per pound, and many references also cite a broader veterinary range of 0.9–1.8 mg/lb (2–4 mg/kg). Always confirm with a veterinarian before dosing your dog. :contentReference[oaicite:2]{index=2}

Dosage by weight (mg) =
Dose(mg) = Weight(lb) × 1

This matches the common 1 mg/lb rule-of-thumb. Some veterinary references cite 0.9–1.8 mg/lb (2–4 mg/kg). :contentReference[oaicite:3]{index=3}

Liquid Benadryl (12.5 mg / 5 mL) =
mL = Dose(mg) ÷ 2.5

Because 12.5 mg / 5 mL = 2.5 mg per mL.

25 mg tablets =
Tablets(25mg) = Dose(mg) ÷ 25

This can be a decimal value depending on weight.

12.5 mg chewable tablets =
Chewables(12.5mg) = Dose(mg) ÷ 12.5

This can be a decimal value depending on weight.

Weight
= Your dog’s weight in pounds (lb)
Dose
= Estimated diphenhydramine amount in milligrams (mg)
mL
= Milliliters of liquid at 12.5 mg / 5 mL concentration

Benadryl Dosage by Weight Chart

Quick reference using the 1 mg per lb estimate, plus common form conversions (liquid is 2.5 mg/mL). :contentReference[oaicite:5]{index=5}

Dog weight (lb)Dose (mg)Liquid (mL)25 mg tablets12.5 mg chewables
5520.20.4
101040.40.8
151560.61.2
202080.81.6
25251012
3030121.22.4
4040161.63.2
50502024
6060242.44.8

How to Use This Calculator

  1. 1

    Enter your dog’s weight (lb).

  2. 2

    Read the dose in mg.

  3. 3

    Use the conversions shown to see the equivalent amount of liquid (mL), 25 mg tablets, and 12.5 mg chewables.

  4. 4

    For dosing frequency, many references cite every 8–12 hours (2–3 times per day), but confirm the schedule with your veterinarian. :contentReference[oaicite:4]{index=4}

Frequently Asked Questions

How much Benadryl can I give my dog by weight?

Many references cite 2–4 mg/kg (about 0.9–1.8 mg/lb) every 8–12 hours. A common rule-of-thumb is 1 mg per pound, but the safest approach is to confirm the exact dose with your veterinarian. :contentReference[oaicite:6]{index=6}

Benadryl dosage for dogs: how often can it be given?

Common guidance referenced by veterinary sources is every 8–12 hours (2–3 times per day), but frequency can vary by dog and situation, so confirm with your vet. :contentReference[oaicite:7]{index=7}

Can dogs take Benadryl capsules or tablets?

Diphenhydramine may be used in dogs, but product selection matters. Avoid combination products with added ingredients unless your vet directs you, and confirm the dose for your dog. :contentReference[oaicite:8]{index=8}

Why does the calculator show Benadryl dosage in mg, mL, and tablets?

Benadryl is sold in multiple forms. The calculator converts an estimated mg dose into liquid (12.5 mg / 5 mL), 25 mg tablets, and 12.5 mg chewables so you can see the equivalent amounts.

Which Benadryl is best for dogs?

Only use a product your veterinarian approves. Plain diphenhydramine products are commonly referenced; avoid multi-symptom versions unless specifically instructed by a vet. :contentReference[oaicite:9]{index=9}