Used Item Price Calculator

Three Ways to Price the Same Item

Nobody knows what a used thing is worth. There is no sticker, and the original receipt stopped being useful the day the box was opened. What you can do is put three numbers on the table and see whether they agree.

Age curve: the new price shrinks by a fixed percentage every year.

Straight line: the value drops by the same dollar amount every year until it reaches salvage.

Comps: the median of what the same thing sold for in the last month.

The first two are formulas, and formulas are only as good as the rate you feed them. The third is evidence. Use the formulas to set a starting point, use the comps to set the number you type into the listing, and use the gap between them to find out which one you trust.

The calculator above runs the first two methods, applies condition and extras, and then checks your answer against a comp if you have one.

The Age Curve: New Price Times (1 Minus the Rate) to the Years

Price after n years = new price x (1 - rate)^n

Compounding is the part people miss. A 35 percent annual drop does not take away 105 percent over three years. It leaves 27.5 percent, because each year's drop comes off a smaller base.

On a $999 phone at 35 percent a year: 999 x 0.65 x 0.65 x 0.65 = 274.35. The first year alone takes $349.65 (999 - 649.35 = 349.65), and the third year takes only $147.72. That shape is why the first owner eats most of the loss and the second owner usually sells for close to what they paid.

The rate is the whole argument. Here are working numbers to start from, not published statistics. Replace them with your own comps as soon as you have three.

Read the third column as a tax rule, not a price forecast. A laptop is fully written off for tax in five years and still sells for a fifth of its price in year six.

Straight Line: For Things That Wear Out on a Schedule

Value = new price - ((new price - salvage) / life) x age

Straight line spreads the loss evenly. It fits things that wear out rather than go obsolete: a chest freezer, a jointer, a shelving unit, a commercial mower. It fits badly for anything a new model can make old overnight.

It is also the method the tax code uses as a yardstick. IRS Publication 946 gives a 5 year recovery period to computers and peripheral equipment and to automobiles, and 7 years to office furniture and fixtures. Mississippi State University Extension's 2026 guide to farm asset depreciation lists the same class lives and works the arithmetic: a $10,000 truck with a $1,000 salvage value over five years loses $1,800 a year ((10,000 - 1,000) / 5 = 1,800).

Two cautions before you trust it on a listing. The tax life is not the useful life, and neither one is the resale life. The salvage value is a guess you make at the start, and it decides a big share of the answer.

Where straight line earns its place is on durable goods with a long, boring service life. A $1,800 dining table that will still hold plates in 2046 has not lost half its value in three years, and a curve built for phones will say it has.

Condition, Extras and Demand: The Three Multipliers

Adjusted price = age price x condition x (1 + extras) x (1 + market)

The formula gets you to the price of a typical unit of that age. Condition, extras and demand move it to your unit and your week.

Extras are worth less than sellers think and more than buyers admit. The original box and manual add roughly 3 to 8 percent on electronics, a spare battery or charger adds 5 to 10 percent, and a receipt with warranty left adds 5 to 10 percent. A missing cable or a lost accessory cover takes off 5 to 15 percent, because the buyer has to go find one.

Demand is the multiplier nobody controls. A new model launch cuts the previous generation by 10 to 20 percent in a week. A discontinued color, a recall, or a viral review can move it the other way. That is what the market adjustment box is for, and it is the one field where your judgment should override the formula.

Worked Example: A Three-Year-Old Phone

A phone bought new for $999, sold at three years old, in good shape, with the box and a spare charger.

1. Age curve at 35 percent a year: 999 x 0.65 x 0.65 x 0.65 = 274.35.
2. Condition, good: 274.35 x 0.85 = 233.20.
3. Box and spare charger, about 8 percent, which brings it to roughly $252.
4. List at the nearest $5 above: $255.
5. Platform fee at 13 percent: 255 x 0.13 = 33.15.
6. Net with no shipping cost: 255 - 33.15 = 221.85.

Notice which step did the damage. The age curve took $725. Condition and extras moved the number by about $23 combined. Sellers spend their time photographing the box and none of it changing the year.

The same phone in fair condition, no box, no charger, lands near $178 before fees (274.35 x 0.70 = 192.05, then a 7 percent deduction for the missing accessories). That is a $77 spread from two words in a listing title, which is why the condition line deserves an honest look in the mirror.

Worked Example: A Dining Table and a Table Saw

Two items, same age bracket, opposite answers.

The table. Solid wood, bought for $1,800, sold at six years, good condition. At 12 percent a year the curve gives 1,800 x 0.88^6 = 835.93. Straight line over 20 years with 10 percent salvage gives (1,800 - 180) / 20 = 81 a year, so after six years the value is 1,800 - 6 x 81 = 1,314.

Those two answers differ by $478, and neither is the market. Sold listings for the same table ran $700 to $900, median $780. Furniture is bulky, pickup only, and buyers discount for the drive and the stairs. The comps win.

The saw. A cabinet saw bought for $650, sold at four years. At 20 percent a year the curve gives 650 x 0.8^4 = 266.24. Straight line over 10 years with 10 percent salvage gives (650 - 65) / 10 = 58.50 a year, so the value is 650 - 4 x 58.50 = 416.

Sold listings ran $300 to $380, median $340. The curve undershot by about $74 and the straight line overshot by about $76, so the market sat between two formulas that disagree by $150.

That is the normal result. The formula brackets the answer and the comps pick the point inside the bracket. If you only have time for one, take the comps.

The Comps Check: Median of Sold, Not Asking

An asking price is a wish. A sold price is a fact. Filter your search to sold and completed listings, then keep the last 30 days, because a two-year-old sold price describes a different market.

Sorted, the seven prices run 240, 245, 250, 255, 260, 275, 310. The median is $255. Listing 4 is a bigger storage tier with a replaced battery, so it is not the same item; drop it and the median of the six that remain is $257.50.

Both answers land within a few dollars of the $255 the formula produced, which is the outcome you want before you type a price. When the comps and the formula disagree by more than 20 percent, believe the comps and go find out why.

Adjust for real differences, not for hope. A storage upgrade, a second battery, a case, and a screen protector are worth what the market pays for them, which you can read off the same comps list.

Fees, Shipping and the Price That Leaves You Whole

The list price is not the money. Marketplaces take a cut of the total the buyer pays, and if you offer free shipping, that comes out of the same pot.

Net = list price - platform fee - shipping you pay

On the $255 phone at a 13 percent fee with $12 shipping: 255 - 33.15 - 12 = 209.85. The phone in your hand is worth $210, not $255.

To work backwards from the number you want, divide by what is left after the fee:

List price = (target net + shipping) / (1 - fee rate)

For $300 in your pocket with $18 shipping at 13 percent: (300 + 18) / 0.87 = 365.52. Check it the other way: 365.52 x 0.13 = 47.52 in fees, and 365.52 - 47.52 - 18 = 300.

Market drift is the last variable, and it is bigger than most sellers expect. The BLS consumer price index for used cars and trucks fell 1.5 percent in the 12 months to September 2026, which means the resale market moved while nothing about those vehicles got a year older in the formula. Your item is not immune. Pull comps from the last 30 days, not from last spring.

One honest test before you list: if the net is under 20 percent of the new price and the item still has years of use in it, the math usually favors keeping it. Selling a $300 appliance for $40 net after fees and a two hour round trip is a donation with extra steps.