What does this loan really cost?

Any loan — personal, auto, student, consolidation. Monthly payment, total interest, and the schedule of what goes where each month.

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Monthly payment
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Total interest
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Total paid
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Interest as % of loan
How is the monthly payment calculated?P&I = L·(r/12)·(1+r/12)^n / ((1+r/12)^n − 1), where L is the amount, r the APR and n the number of monthly payments. A $25k loan at 7% for 5 years is about $495/mo and ~$4.7k in interest.
Why does the first year of payments feel like mostly interest?Interest is charged on the remaining balance, which is nearly the full loan at the start. Over the term it shifts, and the final payments are almost entirely principal. The amortization shown here is that flip happening month by month.
Should I pay extra?If the loan's APR is higher than what your money would earn invested (after tax), paying extra is the guaranteed return. This tool shows the base schedule; every extra dollar amortizes future interest directly.
Is this advice?No — a fixed-rate amortization estimate. Variable rates, fees and prepayment penalties aren't built in; read your note for those.