Car Replacement Sinking Fund Calculator

Most people save for the next car against a fantasy: the price of the car they want, minus what their current car is worth TODAY. But today’s car will be two or three years older on the day it is traded in — worth hundreds or thousands less — and meanwhile it quietly eats repair money that could have been the deposit. This calculator prices the replacement honestly: the trade-in projected forward at a yearly decline rate, the net cost that remains, the monthly set-aside that covers it by your target date — and a repair log that tells you when keeping the old car stops being the cheap option.

What it does for you:
– Start Here — 5-minute setup: target replacement price, current car’s value today, its yearly value decline %, what you have already saved, start and target replacement dates, and the monthly amount you can honestly save.
– Replacement Plan — Months Until Replacement, Projected Trade-In Value at the target date (today’s value declined month-accurately, not today’s number), Net Cost, Still to Save, Monthly Needed and the surplus or shortfall against your capacity. In the samples: a $17,900 target car, today’s $6,800 car projected to $5,046.25 in 28 months, net cost $12,853.75, monthly needed $414.42 against a $450 capacity — the plan fits, by $35.58.
– Repair vs Replace — every repair and running cost logged with a running total, measured against the classic rule of thumb: when keeping costs pass 50% of the car’s value, replacement stops being optional. The samples total $1,900 — 27.9% of value, $1,500 of room left — and the verdict line reads KEEP, in plain words, until the numbers say otherwise.
– Dashboard — target price, projected trade-in, net cost, still to save, monthly needed vs capacity, and the repair total with its % of value, at a glance.
– Expense Log & Monthly Budget — a zero-based budget with Car Fund and Car Repairs categories, so the set-aside and the old car’s appetite are both visible in the same month.
– Sample rows pre-filled so every formula works the moment you open it; formula cells are locked (password disclosed in Start Here) and every formula is error-wrapped. Values and decline rates are estimates — every car’s market differs. A planning tool, not financial advice.

What’s inside (.xlsx, works in Excel AND Google Sheets): Start Here · Replacement Plan (projected trade-in + monthly needed) · Repair vs Replace (cost log + 50% verdict) · Expense Log · Monthly Budget (zero-based) · Dashboard · Monthly Summary (12 months).

Instant download. No shipping, no waiting. Message us if you need help setting it up — we answer fast.