Commercial Lease Payment Calculator Needed for Property Agency Site

Our commercial real estate agency needs a developer to build an interactive rent calculator for our website. Right now potential tenants have to call or email us just to get a rough estimate of monthly lease costs, and a good share of them leave the site instead of waiting for an answer. We want visitors to enter a few basic parameters themselves and immediately see an estimated monthly payment, including utility costs, before deciding whether to contact an agent at all.

The calculator should let the user choose the type of premises (office, retail, warehouse, or production space), enter the floor area in square meters, and select the lease term, since our pricing changes for short-term versus long-term contracts. The result screen should show the base rent separately, an itemized estimate of utility charges, and a total monthly figure, with a button to request a callback without leaving the page. The layout needs to match our current site style and work correctly on phones.

Requirements for the build:
— clean, commented code with pricing coefficients kept separate from the logic
— responsive layout tested in the major browsers
— clear validation of input fields with helpful error messages
— an analytics event fired whenever a calculation is completed