Should you build or buy software? This Wall Street firm has a new tool to decide.

RBC Capital Markets developed an interactive tool to address the build-versus-buy debate surrounding business software. The calculator allows users to compare subscription costs with the full cost of building and running an in-house alternative, factoring in maintenance, security risks, and repairs. RBC's analysis found that building core systems—such as payroll or customer records—is usually more expensive than simply purchasing the required software.