Sizing, Model and Fit

Which shoe is right for me?

We can help you right here.

What size should I get?

Please use the ShoeFitr application (located on each shoe page) in order to help with an accurate size estimate.

How do I know if my shoes fit properly?

The ideal fit with Newton shoes is with the bones of the ball of your feet directly over the center of the raised lugs on the outsole of the shoes.

This alignment typically offers a thumb's distance of space in front of the longest toe to the end of the shoes.

Is it okay to use orthotics with Newtons?

Yes.  Simply remove the sock liner that comes stock in the shoes, and replace it with your over-the-counter or custom insole.

For custom orthotic information, contact the Newton Running Lab at 303.494.0321

Do you have a wide model?

Yes, the Sir Isaac Wide Guidance Trainer accommodates a 2E width foot.

Am I too big/heavy to wear Newtons?

It is unlikely you are too heavy for Newton Running Shoes. The technology used in all Newton Running shoes works like a trampoline – when your foot strikes the ground, the raised lugs on the outsole compress through a stretch membrane into a hollow chamber in the midsole. Since when were you too heavy for a trampoline?

If you are currently running with a heavier heel strike, we encourage you to modify your gait to a more natural running stride. In this case, you may find our Guidance Trainers (M/W) the best in terms of fit and function.

Newton Running: Shoe Facts and Details

What should my wear pattern look like?

Newton Running shoes are designed to show wear from the outside-in.  It’s one of the most helpful bits about our shoes, and your unique wear pattern can teach you a lot about how you’re running.

Ideal wear on your Newtons is with friction accumulation on the front third of the raised lugs under the ball of the foot, and the rear two-thirds showing less wear.  Friction wear in front of the raised lugs represents excessive toe-off; efficiency can be gained by focusing on lifting from the hip flexor at the end of the stride rather than pushing off from the toe.  Mild friction wear on the heel is nothing to be alarmed about.

How many miles will my Newtons last?

All Newton Running shoe models other than the MV2 have a lifespan of 350-500 miles (500-800 km).  The MV2 is a racing flat with a 150-200 mile lifespan.

If you've not tracked your mileage, you can base your need for new Newton Running shoes on how they feel – when you feel like your Newton shoes are no longer giving you the same "pop" they once were, it's time for a replacement.

How do I clean my Newton shoes?

The best way to clean Newtons is by hand.  The shoes are not designed to tolerate the agitation and extreme conditions of a washer/dryer.  We recommend scrubbing them in the sink, using a mild detergent and an old toothbrush.  The insoles should also be cleaned by hand, or if they get past the point of cleaning, simply replace them with an over the counter insole replacement such as Spenco.  

Where are Newtons made?

Newton Running is a Boulder, CO based company – all the design, research, and wear testing is done here locally, but our shoes are produced overseas in our factories in Indonesia and China.  

Adjusting to the Shoes

Can I rotate my Newtons with my old shoes?

As you transition to your Newtons you can continue to rotate them with your more traditional running shoes. When starting out, we recommend using your Newtons for 15-20 minutes at a time and your other shoes for the rest of the mileage you want to log as this will help you adjust to the more level platform and unique technology in our shoes. You'll notice that the more you're in your Newtons, the less you will want to be in your old shoes!


My calves are sore. Are yours?

Running with a more natural running technique engages the Plantar Fascia, Achilles tendon and calf with every foot strike. These muscles and tendons work very efficiently in unison but they are tiny and, therefore, susceptible to fatigue. Some slight soreness as you adjust to your Newtons is totally normal and nothing to worry about - it just takes some time to build strength and lengthen those muscles and tendons so be patient and take your time breaking in your shoes.

How long will it take to adjust to my Newtons?

Everyone's a little different with how they adjust to their Newtons; some take a week, and others take months.  Start with runs of 15-20 minutes, while continuing to log the bulk of your mileage in your traditional running shoes.  The best advice is not to do too much too soon; be deliberate with your time in the shoes, and cognizant of how you feel as you go.

Click here for more information.

Running Form & How to use Newton Shoes

Can I run long in Newtons?

Definitely!  Your Newton shoes are built to take whatever distance you want to log in them, whether it's 5 km or 500 km.  The only models that are built specifically for shorter distances are our racing flats the MVand Tri Racer.

Can I run in both my Newtons and traditional running shoes?

As you're adapting to your Newtons, we recommend that you switch back and forth with your traditional shoes. However, once you have completely adjusted to your Newtons, they are designed to be your full-time training and racing shoes.  

How do I run midfoot downhill?

Running downhill with a midfoot strike takes a bit of time to master.  A confident, rapid leg turnover will allow you to stay on the midfoot while continuing to accelerate on the downhill. Keep your feet level to the ground rather than pointing your toes down and stabbing the ground or overstriding and braking with your heel. Watch a demontration here

Good resources and information on Natural Form Running

Newton Running Cofounder Danny Abshire’s book Natural Running is an outstanding resource for people interested in learning more about running efficiency and form. Other resources include:



What is the MV3?

The MV3 is a "zero-drop" shoe engineered for athletes who practice Newton running form. The MV3 is unique in that it is built on a level profile: There is no drop from the heel to the midfoot, hence the term “zero drop.”

It is not unusual for runners who are transitioning to a zero-drop shoe like The MV3 to experience tightness in their calf muscles and Achilles tendons, as well as their feet. This can occur because the muscles and tendons are further elongated when running in a zero-drop shoe, compared to a conventional shoe with a lifted heel.

Adapting to a zero-drop shoe and a Newton running style takes time, and the process is unique for each athlete. It is always better to make this transition gradually. With this in mind, we enclose a removable 3 mm heel lift with each pair of our MV3 models in the event that you wish to transition with incremental steps. This is particularly recommended if you are transitioning from a shoe with a high heel-toe drop.

What are the details of the MV3?

The MV3 runs a bit more snug than other Newton shoes, but most runners are wearing the same size in the MV3 that they wear in their other Newton shoes.


Built as a racing flat, the MV3's lifespan is 150-200 miles.


The MV3 is meant for tempo runs, interval sessions, and 5k/10k racing.

Should I use the enclosed heel lift?

As most running shoes have a heel to toe drop, it can be challenging to adapt to the totally level platform of the MV2.  Starting out with the 3mm heel lift offers you the opportunity to gradually elongate the lower leg and foot muscles/tendons.  Once acclimated to the 3mm drop, you can remove the heel lift if you'd like.

How long will the MV3 last?

The MV2 provides much greater longevity than typical racing flats if you are running efficiently. As with all of our shoes, the MV2 wears like car tires – you will begin to see wear externally on the lugs almost immediately. It’s time for a new pair when you feel like your MV2s are no longer giving you the same "pop" they once were.

What is "second generation" Action/ReactionTM technology?

The membrane is lightweight and tuned to react faster, promoting higher cadence. The lower-profile design includes five articulating lugs.

Who should wear the MV3?

Anyone can run in the MV3.  As the MV3 is meant for tempo runs, and 5k/10k racing, it's best kept as an "addition to" rather than an "instead of" shoe in your Newton collection.

What distances can I run in the MV3?

The MV3 is meant for shorter, quicker training runs, and 5k/10k racing.  If you're looking to run longer distances, we recommend our other Performance shoes.

Can I use the MV3 on trails?

The shoes are nimble and offer great traction. They can be used on paths and dirt roads, but MV3 was not designed for rugged terrain. The uppers are not designed to provide lateral support and there is no protection for hitting hard objects like rocks and roots.

Purchasing, Exchanges & Returns

I'm getting an error message when I place my order. Why?

This is usually due to the billing address not matching what the bank has on file for your credit card.  You can change that address and try again, or you can simply contact Customer Service 303.442.1113 to place your order over the phone.

There are multiple authorizations against my credit card. Why?

When you place an order, we authorize your credit card to confirm it is valid and that there are sufficient funds available for your purchase. 

An authorization does NOT charge your card at that time, but some banks may hold the authorization for the purchase amount on a customer's card for up to 7-10 business days.  It will appear on your statement as a 'pending charge' and is usually for a dollar more than the original purchase amount. 

We do not charge your credit card until your item(s) have been shipped.

If your order has been split into multiple shipments, we will only collect payment on the portion of your order that has shipped. 

Please review your shipment notification email for details on the amount actually charged to your credit card.

If you wish to remove the authorization, please contact your credit card's issuing bank.  

How do I find my tracking number?

Once your order has shipped, you will receive an email confirmation.  This email will include your UPS tracking number and a link to the UPS tracking website. 

How do I exchange my shoes?

Return authorizations are required for all exchanges. Pleease contact Newton Running Customer Service at or 303-442-1113 within 30 days of your purchase to exchange your Newton shoes.

How do I return my shoes?

Return authorizations are required for all returns. Please contact Newton Running Customer Service at or 303-442-1113 within 30 days of your purchase to either exchange your Newton shoes or return them for a refund.

Do you have a guarantee?

We offer all our customers in the US and Canada the same 30-day, no-questions-asked return and exchange policy on all shoe purchases. 

Is there a retailer near me?

Our retail and international distribution partners can be found on the Retail Locator page.

Global Responsibility

What does Newton Running do to improve the world?

Newton Running cofounders Jerry Lee and Danny Abshire created the company with the desire to give back and improve our world. Visit our Global Responsibility page to learn more.

What are Newton's policies regarding responsible production and human rights protections?

The Newton Running Human Rights Production Standards reflect the relevant covenants of the International Labor Organization, input from human rights organizations and academia, and our own experience. In developing this policy, we sought to use standards that are fair, appropriate to diverse cultures and that encourage workers to take pride in their work.


Newton Running will seek business partners who do not discriminate in hiring and employment practices, and who make decisions about hiring, salary, benefits, training opportunities, work assignments, advancement, discipline, termination and retirement solely on the basis of a person disability to do the job.

Working Hours/Overtime

Workers shall not be required to work more than 60 hours per week, including overtime, except in extraordinary circumstances. In countries where the maximum work week is less, such local standard shall apply. Workers shall be entitled to at least one day off in every seven-day period. Adherence to this Newton Running Standard is a sign that factory management efficiently organizes its production planning and workflow.

No Forced Or Compulsory Labor

No factory making Newton Running products shall use forced or other compulsory labor, including labor that is required as a means of political coercion or as punishment for holding or for peacefully expressing political views. Employers will maintain sufficient hiring and employment records to demonstrate and verify compliance with this provision. Newton Running will not purchase materials produced by any form of compulsory labor and will terminate business relationships with any sources found to utilize such labor.

Fair Wages And Benefits

Newton Running will seek business partners committed to the betterment of wage and benefit levels to the extent appropriate in light of national practices and conditions. Newton Running  will not select business partners who pay less than the minimum wage required by applicable law or who pay less than the prevailing local industry wage.

No Child Labor

Newton Running seeks business partners who do not use child labor. The term "child" refers to a person who is younger than 15, or younger than the age for completing compulsory education in the country of manufacture, whichever is higher.

Freedom Of Association

Newton Running will seek business partners that share its commitment to the right of employees to establish and join organizations of their own choosing. Newton Running  recognizes and respects the right of all employees to organize and bargain collectively.


Newton Running will seek business partners that treat their employees with respect and dignity. No worker will be subject to any physical, sexual, psychological, or verbal harassment or abuse.

Safe And Healthy Work Environment

Newton Running will seek business partners that strive to assure employees a safe and healthy workplace and that do not expose workers to hazardous conditions.

Non-Retaliation Policy

Factories must publicize and enforce a non-retaliation policy that permits factory workers to express their concerns about workplace conditions without fear of retribution or losing their jobs. Workers should be able to speak without fear directly to factory management or Newton Running representatives.

Environmental Footprint

Newton Running will work with our partner suppliers to promote positive environmental awareness and responsible practices.

Education, Events & Expos

Are there any upcoming events in my hometown that highlight Newton Running?

We're on the road all the time! Come see us at a running or triathlon expo, form clinic, or educational symposium.

Corporate Information & Programs

How can I reach someone at Newton Running?

Visit our Contact Us page for more information on how to call or email us.

Do you offer Active Duty Pricing?

We do!  Newton Running is proud to support our active duty Military, Police, and Firefighters by offering a 20% discount and free shipping on all orders placed through our website. Are you active duty?  Apply Now!

Do any professional athletes run in Newton Running Shoes?

Yes! Newton Running’s pro-team includes many world champions, ultramarathoners and triathletes. Visit our Athletes page to learn more.

Job opportunities?

In the event that job openings become available with Newton Running, you will see them posted under the Careers section of our website.


In the case that job postings become available with Newton Running, you will see them listed in the [Community][LW1] section of our website.

 [LW1]Link to Careers page.