Calculate the total cost of a security system using your quotes

Start with the scope of the offers. An installation that records footage and a service that includes reviewing it do not meet the same need. Compare figures after clarifying this distinction.

Then choose the same whole number of months for every offer. State whether amounts include or exclude tax, without mixing the two. Keep the date, validity period and reference of each quote. If an amount may change, show this uncertainty rather than hiding it in an average.

“Other recurring charges” can also accommodate an irregular payment schedule. If a monthly charge changes during the period, add the known payments in this category and enter zero in the corresponding fixed monthly field. Document the allocation to avoid counting the same payments twice.

For rental or a subscription, check the term, renewal and end conditions. For a construction site, match quantities to the phases actually being considered.

Enter the duration and the six amounts in CHF. For non-monthly recurring charges, one-off expenses, variable charges and exit costs, enter the total for the entire period. The calculation stays in your browser; this tool does not send these amounts anywhere.

A result appears only when every input is complete and valid. The form does not turn an empty field into zero expenditure. Apostrophes as thousands separators and decimal commas are accepted.

Total = initial costs + (fixed monthly charges × number of months) + other recurring charges over the period + one-off costs + variable scenario costs + exit costs.

If maintenance is billed on specific annual dates, count the payments scheduled in the offer. Do not automatically prorate the duration in months. A period shorter than a year can still include a full annual payment; only the contractual schedule determines this.

To check the result, match each category to one or more lines in the quotes. Check inclusions, duplicates and expenses handled by another supplier. A connection or visit paid for separately belongs in the comparison if it is needed for the same scope.

The CSV sheet lets you keep your assumptions and references. It contains no prices or spreadsheet formulas; calculate in the tool above or in your own file.

Prepare a base scenario using confirmed charges and the selected quantities. Add a useful change scenario: extending a construction project, moving equipment, changing a package or arranging an extra visit. Request applicable rates before pricing that change.

In a fictional example, a construction site has a quote for an initial duration, but an extension remains possible. The first comparison covers the planned duration. A second adds the payments and visits corresponding to a chosen extension. Both results remain tied to their scenarios: together they do not constitute a certain estimate of the final cost.

The total helps you identify differences and find their causes. Check whether a difference comes from equipment, an additional service, a term commitment or an expense left to you. Do not reduce the decision to the difference in price when the scope still differs.

Maintaining connected devices also involves operational work. The NCSC recommendations call for assigning updates and access management. The time spent on these tasks can be described separately; do not attach an arbitrary monetary value to it to favour an offer.

Before selecting a proposal, return to evidence of operation, the division of tasks between technology and people, and exit conditions. For a villa, the detailed budget checklist helps check the technical items in the project.