Log in to your uCalc account and go to the page with the list of your projects. Open the menu and click on the Get code button. The window with the embed HTML code will appear:
Go to managing your Squarespace site, hover over the block and click Edit:
Choose the place where you’d like to add the calculator and click on the special switcher:
Under the More section, choose the Code widget:
Paste there the calculator code you copied before (1) and click on the Apply button (2):
Click Save:
Your calculator is ready!