Calculate the true first-year cost of SaaS
Include seats, onboarding, migration, integrations and internal time in one comparable model.
Normalize the subscription
Convert monthly and annual quotes to the same period and currency. Include required plan tiers, minimum seat commitments, usage charges, premium support and taxes where applicable.
Ask what happens when headcount changes during a contract. A low introductory price can be less important than the renewal basis and the rules for removing seats.
Expose implementation work
Migration, data cleanup, configuration, training and integration testing consume staff time even when the vendor charges no setup fee. Estimate hours by role and assign an internal planning rate.
Treat unknown integrations as a risk range rather than a zero. A short technical proof using representative data can reduce uncertainty before a longer commitment.
Compare a realistic year
Model expected user growth, normal usage and likely add-ons across twelve months. Keep a separate scenario for minimum viable use so the team can see which costs come from optional complexity.
Record the assumptions next to the result. The calculation is useful because it makes disagreements visible, not because it predicts every invoice exactly.