calculus T-Shirts

For over 15 years, we have been designing some of the most popular t-shirts and tank tops around. We design, print, and ship out all the t-shirts that we showcase on this website. With 10,000+ designs available, we offer tees for just about any interest or topic you can think of. Our customers include A-list celebrities, influencers, and very possibly somebody you know.

Most orders ship out within 3-4 business days from our warehouse in California via USPS 1st class mail.
If you want them ASAP, we offer 2 options...

• Choose "expedited manufacturing" in checkout to get a cut in line of other orders to be printed.
• Order more shirts(we have over 10,000 designs to choose from!).Any package that weighs over 1lb will automatically be shipped USPS priority mail. This is usually 4 mens XL shirts. For womens and kids styles, it may be 5 or more.

Our shirts are designed & printed in northern California. The shirts we use come from a variety of ethically sourced countries and also made in the USA.

We are happy to offer easy exchanges within 30 days of the delivery of your order if you would prefer a different size. You can find our full return & refund policy as well as the instructions for making an exchange in the footer of the site

• For most orders, standard shipping is $6.99.
• Shipping with Expedited Manufacturing for most orders is $10.95

We provide a size chart linked above which provides general sizing as well as fabric content and other details for the style & color that you have currently selected.