Two ledgers, one run
A build that looks affordable on paper can still fail in play, because points and time are two different ledgers. The skill points & XP guide makes the point: every perk you learn also costs time segments at a road shrine, and the 30-day clock caps how many of those you will ever afford. This planner checks both at once.
The point ledger
Your pool minus your reserve is what you can commit. Each perk costs a point, so the point cost is just the number of perks. If that exceeds your pool, the plan is over-committed before a single section is spent. The build calculator is where you decide how the committed points split across Swordmastery, Witchcraft and Vampirism; this tool only asks whether the total fits.
The time ledger
Each perk also burns about 1–3 sections of the 480-section clock, so the time tax is perks × average segments. A plan that is point-cheap but time-heavy will still run you past day 30. The conservative average is 2 per perk; higher-tier perks cost more, so if your plan leans on late-tree perks, nudge the average up and re-check.
Working together
Use the time ledger to see how much of the window your perk plan leaves for story and optional content, and use this planner to confirm the plan itself fits the clock. If both are green, you can commit; if the time tax is red, cut perks before you spend a single point.