American Standard System of Measurement

This page discusses the American Standard System of Measurement.

Pharmacy Technicians need to be familiar with several systems of measurement to perform the everyday tasks required in a pharmacy.

The American Standard system of measurement is important because it will be the one most familiar to your customers.

And it's important to be able to explain dosage information in terms they can easily understand and recall later.

The American Standard system is also referred to as the Household system.

Volumes of liquid are measured in:



Fluid Ounces





Conversions within the Household system are as follows:

3 teaspoons = 1 tablespoon (one-half of a fluid ounce)

2 tablespoons = 1 fluid ounce

8 fluid ounces = 1 cup

2 cups = 1 pint (16 fluid ounces)

2 pints= 1 quart (32 fluid ounces)

4 quarts = 1 gallon (128 fluid ounces)

Weight is measured in:



There are 16 ounces to a pound.

Length is measured in:





12 inches = 1 foot

3 feet = 1 yard

1760 yards = 1 mile(5280 feet)

The most common calculations you'll need to make will be converting a metric measurement into an American standard measurement.

Kilograms into pounds or milliliters into teaspoons for example.

Here are the most common Metric to Standard conversions that you will encounter.

1 kilogram (1000 grams) = 2.2 pounds

3.8 liters (3800 milliliters) = 1 gallon

5 milliliters = 1 teaspoon

15 milliliters = 1 tablespoon

29.6 milliliters = 1 fluid ounce

It's important to memorize these conversions and also to understand which unit is larger.

This makes it easy to double check a conversion to ensure you did it correctly.

For example, we know that a kilogram weighs more than a pound.

So after converting 5 kilograms, we can look at our answer(11 pounds) and understand that it looks correct.

Teaspoons and tablespoons from milliliters is another common conversion.

Most liquids will be measured in either teaspoons or tablespoons for the customer.

So it's important to understand that when preparing and dispensing medications.

With a little practice, these conversions will become automatic. Just remember to be careful and never add a decimal place at the end of a whole number.

2 ounces for example, will never be written as 2.0 ounces. Decimal places and periods are the most common causes of mistakes in pharmacies.

So remember to take the extra time to double check every conversion you make and explain everything in simple and easy to understand language for the customer.

Top of American Standard System of Measurement

Back to Pharmacy Technician Math

Back to Home

This PREMIUM Collection of Pharmacy Tech Resources Might Just Transform YOUR Career! 

Plus... ALL the RESOURCES below:

I'd like to get this collection into the hands of as many Techs as possible, so we have lowered the price: Normally $24.99, but NOW, 65% OFF, for a LIMITED TIME ONLY.





ALL Resources below are
included in this informative COLLECTION:

Volume #1
(4-Ebook & 4-Report Bundle)
PharmTech Fundamentals and More

Report: Drug Development in the US
Pharmacy Technician Settings
Latin Medical Abbreviations
Resolving Prescription Insurance Rejections:
(NOW updated with DUR Codes)

Report: Telephone Etiquette for PharmTechs
NEW Report: Cough & Cold Remedies AND Decongestants 
NEW Report: Top 200 Medications - 
Brand Name/Generic/Condition

Volume #2
(6-Ebook Bundle)

HIPPA and The PharmTech
How to Become a Pharmacist/Roadmap to RPH
Pharmacy Systems of Measurement
Pharmacy Dosage Forms
Keys to PharmTech Career Success
Time Management for PharmTechs

National Certification Bundle 
(1-Ebook & 5-Practice Test Package)

USA PharmTech Certification Demystified
Unofficial PTCB Exam Practice Test #1: Q&A

Unofficial PTCB Exam Practice Test #2:
(Exclusively MATH Q&A, with extensive answers)
Unofficial PTCB Exam Practice Test #3: Q&A
Unofficial PTCB Exam Practice Test #4: Q&A
Unofficial PTCB Exam Practice Test #5: Q&A

Rx Errors & Pharmacy Safety Package
(1-Ebook & 2-Report Bundle)

Coping With Pharmacy Errors
Report: Pharmacy Root Cause Analysis
Report: Improving Pharmacy Safety Culture

Navigating Challenging Environments Package
(1-Ebook & 2-Report Bundle)

Best Practices for the Assertive PharmTech
NEW Report: How To Cope With A Hostile Workplace

NEW Report: Managing Overwhelm At The Pharmacy

Free Bonus Ebook:
NEW: The Canadian PharmTech's Quick Start Guide

GRAB this valuable, Premium Collection NOW!

Normally $24.99, but now
**65% OFF**
 Use code "SUMMER20" to get YOUR discount!


Pay via Paypal for IMMEDIATE Download :)

Click Buy Now to get YOUR COPY of this
Premium PharmTech Package, before this deal is gone!

Back to Home

New! Comments

Have your say about what you just read! Leave me a comment in the box below.
[?]Subscribe To This Site
  • follow us in feedly
  • Add to My Yahoo!

Recent Articles

  1. 1 tablet as needed every 12 hours for 30 days, QTY 60

    Mar 02, 22 09:52 PM

    what is the quantity and days supply?

    Read More

  2. Days supply

    Mar 02, 22 09:43 PM

    If a patient takes a tablet just twice in a week and 18 tablets were dispensed, what is the days supply?

    Read More

  3. How do I do an RX Buyout using InterCom Plus?

    Mar 02, 22 09:24 PM

    How do i do a rx buyout using IC+?

    Read More

  4. CONVERSIONS-Glucose 10g from 5% solution in 500ml Normal Saline. How much NS do you need for 10g of Glucose?

    Mar 02, 22 09:21 PM

    Patient is prescribed 10g of Glucose. The glucose is presented as a 5% solution in 500ml Saline. How much of the 5% dextrose saline solution do you need

    Read More

  5. Yea I'm stuck...HELP breakdown with answer

    Mar 02, 22 09:19 PM

    I have a 70% solution and a 15% solution and I am asked to make 480ml of a 30% solution. What parts of each strength will be used and what's the final

    Read More

  6. Amoxil 50ml 125ml/5ml Suspension-What is the days supply?

    Mar 02, 22 09:16 PM

    125mg/5ml dispense 50ml tsp bid

    Read More

  7. 45 pills @.5 per day =

    Mar 02, 22 09:11 PM

    How long will 45 pills taken at .5 pill per day last?

    Read More

  8. Solve this

    Oct 29, 21 06:41 PM

    2 tablets 4 times a day for 30 day supply. 26 per bottle.

    Read More

  9. Celebrex: Take 1 capsule PO BID, start 1 day prior to surgery and continue for 3 weeks

    Oct 29, 21 06:32 PM

    take one capsule by mouth twice a day with meals. start 1 day prior to surgery. continue for 3 weeks after surgery.

    Read More

  10. My dog takes 2/3 of a tablet 2 times a day how many do I need for 90 days?

    Oct 22, 21 10:48 PM

    My dog takes 2/3 of a tablet two times per day. How many tablets will I need for 90 days?

    Read More

  11. Premarin Cream applied every 72 hours for 30 days-How many days supply is that?

    Oct 06, 21 03:44 PM

    How many days is it when Premarin cream is applied every 72 hours for 30 days?

    Read More

  12. 45 pills @ 0.5 per day = How long will the rx last?

    Oct 06, 21 03:40 PM

    How long will 45 pills taken at .5 pill per day last?

    Read More

  13. Amoxil 375mg po BID. Pharmacy dispenses 150ml of Amoxil 250mg/5ml. How many days will it last?

    Oct 06, 21 02:45 PM

    A patient has a prescription for Amoxil 375mg po BID. The pharmacy dispenses 150ml of Amoxil 250mg/5mL suspension. How many days would the medication last

    Read More

  14. A DROP OF LUMIGAN IN EACH EYE DAILY-How many 2.5 ML bottles to fill a 90 day supply?

    Oct 06, 21 02:06 PM


    Read More

  15. Find the day supply please humulin 70/30 2x10ml Vials 100u/1ml

    Oct 01, 21 10:59 PM

    humulin 30/70 15 u at breakfast and 30 u at dinner M: 2 vials (10ml) 15 u + 30 u = 45 u concetration = 100u/1ml 45u/100u = 0.45 ml 2 vial = 20 ml / 0.45

    Read More