Free calculators for collectors and phone owners
Working tools, not lead-capture forms. Each one runs entirely in your browser — nothing is uploaded, nothing is stored on our side, and none of them ask for an email address. The fee tables behind the card tools carry the date they were last checked against the grading companies' own price lists.
Grading & condition
The arithmetic behind a submission: what grading costs at each company, what centering and condition allow, and whether the card is worth sending at all.
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Card Grading Cost Calculator
Price one submission across PSA, BGS, CGC, SGC and TAG, postage included — and see which tiers are paused right now.
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Is It Worth Grading? ROI Calculator
Expected value of grading against selling raw, and the break-even Gem rate that decides it.
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Card Centering Calculator
Border measurements to a centering ratio, and the highest grade that ratio still allows.
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Card Grade Estimator
Score centering, corners, edges and surface and get the grade those scores imply.
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Grading Scale Converter
One grade translated across PSA, BGS, CGC, SGC and TAG, with the condition each number means.
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Grading Turnaround Planner
Published business days turned into a calendar date, and what each faster tier costs per week saved.
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Grading Submission Planner
Which cards clear the bar on your budget, which tier each belongs on, and where the cut-off falls.
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Card Dimensions Checker
Measure a card against the standard for its era to find out whether it has been trimmed.
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Fake Card Detection Checklist
The checks that separate a genuine card from a counterfeit, weighted by how conclusive each one is.
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Card Cleaning Risk Checker
Which cleaning actions count as alteration, which void a grade permanently, and what graders detect.
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Autograph Authentication Compared
Authentication services on cost and market acceptance, and when certification pays for itself.
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Serial Number Scarcity Calculator
What /99 really means once every parallel of the same card is counted.
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Rookie Card Checker
Whether a card is a true rookie, a prospect card, or a later-year card that only looks like one.
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Card Supplies Calculator
Sleeves, toploaders, pages and boxes for a collection, with what protection costs per card.
Selling, fees & tax
What you actually keep. Marketplace and auction-house commissions, postage, consignment splits, and the tax treatment that decides whether a profitable year is really profitable.
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Card Selling Fee Calculator
What you keep on eBay, TCGplayer, Whatnot, Mercari and COMC, including the high-value discount.
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Auction House Fee Calculator
What a card nets at each auction house once seller commission and buyer premium are counted.
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Buyer Premium Calculator
The true cost of winning at auction, and the maximum bid that keeps you inside budget.
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Consignment vs Selling Yourself
Commission against fees, and the premium a specialist audience has to pay to justify it.
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Card Shipping Cost Calculator
The cheapest safe way to post a card at its value, at 2026 USPS rates.
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Collectibles Tax Calculator
US tax on card sales under all three classifications, including the 28% rate and the 1099-K threshold.
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Card Flipping Profit Calculator
Real margin after fees both ways, postage, tax and the capital tied up while you wait.
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Collection Insurance Calculator
Whether home insurance covers your collection, and what a rider or specialist policy costs.
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Collection Value Tracker
A private ledger of what your cards cost and what they are worth — saved in your browser.
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Card Lot Pricing Calculator
What to ask for a bulk lot, and whether pulling the best cards out first beats selling it whole.
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Bulk vs Singles Calculator
The price below which a card belongs in the bulk lot rather than its own listing.
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Best Offer Negotiation Calculator
What to offer on a listed card, and what that offer actually nets the seller.
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Card Show Table ROI Calculator
Whether a show table pays: fee, travel, hotel and hours against realistic footfall.
Sealed product & breaks
Expected value on boxes, cases and break slots, pull-rate odds, and the maths that shows why sealed product is priced the way it is.
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Booster Box EV Calculator
Expected value of opening sealed product, against what the box costs and sells for sealed.
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Pull Rate Calculator
Real odds of hitting a card over any number of packs, and the packs needed for even odds.
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Break Slot Value Calculator
Whether a team slot is priced fairly against the share of the box that team can produce.
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Team Break Odds Calculator
The chance a team produces a hit, from the hits in the box and its share of the checklist.
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Case vs Box Calculator
The per-box discount, case-only hits, and how much the extra volume really cuts variance.
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Hobby vs Retail Box Comparison
Hobby, blaster and mega on cost per hit and expected value, including retail exclusives.
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Razz Fairness Calculator
Whether a card raffle is priced fairly: your odds against the margin the organiser takes.
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Group Break Cost Splitter
Price break slots by demand so the room fills, with the margin you actually need.
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Set Completion Calculator
Cost to finish a set as singles against packs, with the coupon-collector maths behind it.
Boxes of old cards
For the collection that arrived in a loft rather than from a hobby shop: what era it is from, what it is realistically worth, and whether sorting it is worth the weekend.
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Bulk Collection Value Calculator
What a box of old cards is realistically worth, by era and condition.
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Junk Wax Era Checker
Enter the year on the back and find out whether it comes from the era printed into worthlessness.
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Inherited Collection Planner
Four ways to handle an inherited collection, priced side by side with hours and net.
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Card Sorting Time Calculator
Hours to sort a collection, and whether sorting beats selling the box unsorted.
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Card Year Identifier
Work out the year of a card with no date on it, from the statistics on the back.
Player stats & fantasy
The formulas behind the numbers on the back of the card, and the ones that decide a fantasy season — computed rather than looked up.
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Baseball Batting Stats Calculator
Batting average, on-base, slugging and OPS from a counting line, with each formula shown.
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ERA and WHIP Calculator
Pitching rates from innings and the raw line, with the thirds-of-an-inning conversion handled.
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NFL Passer Rating Calculator
Passer rating with all four components shown separately, and why it maxes at 158.3.
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Basketball Efficiency Calculator
True shooting and effective field goal percentage, which weight shots by what they are worth.
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Hockey Goalie Stats Calculator
Save percentage, GAA and goals saved above average from a goaltender line.
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Season Pace Calculator
What a player is on pace for, and how little early-season pace actually predicts.
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Hall of Fame Odds Calculator
A career scored against what voters reward, and what induction does to card prices.
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Fantasy Trade Value Calculator
Score a trade on value over replacement, including the roster-crunch effect on 2-for-1s.
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Fantasy Auction Budget Calculator
How much to spend per slot, what to reserve, and the highest bid you can still make.
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Fantasy Points Calculator
A stat line converted to points under PPR, half-PPR, standard and TE premium at once.
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Keeper League Value Calculator
Which players to keep, by surplus against their draft-round cost with escalation.
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Playoff Odds Calculator
The chance of reaching a win total from a record and remaining schedule.
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Survivor Pool Calculator
Odds of lasting the season, and why saving the best teams beats using them now.
Directories & comparisons
Who does what, what it costs, and which one fits your card. Kept current with the date each fee schedule was last read.
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Card Grading Companies Compared
Every grader on price, wait, resale premium and what each is actually respected for.
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PSA Alternatives
Where to grade while the PSA value tiers are paused, and whether the premium covers the gap.
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Card Auction Houses Compared
Commission, buyer premium, minimums and what each house is genuinely strong at.
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Where to Sell Sports Cards
Every venue compared by fee, audience and the card values each one actually suits.
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eBay Alternatives for Selling Cards
What you would actually receive elsewhere, allowing for the smaller audience each brings.
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Whatnot vs eBay for Cards
Commission, realised price and hours, priced against the inventory you actually have.
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Card Scanner Apps Compared
Scanner apps on identification accuracy, pricing source, free tier and subscription cost.
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Who Makes Cards for Each League
Current licence holders after the Fanatics takeover, and what it means for your cards.
Phones, apps & storage
Storage, data, download and display maths for Android and iOS, including the developer-side numbers behind Play Store payouts and density buckets.
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Phone Storage Calculator
What actually fits in 128 GB once the system takes its share.
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Download Time Calculator
How long a file takes at any speed, with the megabit-to-megabyte conversion done properly.
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Mobile Data Usage Calculator
How many gigabytes a month your habits use, and the plan size that covers them.
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Internet Speed Requirements
The connection speed a household needs, from what everyone does at once.
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File Size Converter
Bytes to terabytes, decimal beside binary — and why a 1 TB drive shows 931 GB.
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Screen DPI Calculator
Pixel density, Android density bucket, dp dimensions and the acuity limit.
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Aspect Ratio Calculator
Ratios, proportional resizing and the screenshot sizes each app store requires.
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Android Version and API Level Lookup
Every version to Android 17, with API levels, codenames and Play deadlines.
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App Store Revenue Calculator
What a developer keeps after the 2026 Play fee split and the million-dollar threshold.
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Subscription Cost Calculator
What your app subscriptions really cost per year and over five, and which to cancel.
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Screen Time Calculator
Daily hours turned into days a year and years a lifetime.
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Battery Life Calculator
mAh to real hours by activity, charging time and capacity loss over years.
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Gacha Pity Calculator
Odds including soft pity, hard pity and the 50/50, plus what a guarantee costs.
How these were built
Every calculator on this page is hand-written JavaScript with the formula stated on its own page. Where a tool depends on outside numbers — grading fees, marketplace commission rates, Android density buckets — those numbers are typed in by hand from the primary source and stamped with the date they were read, because they move. A grading fee that was right in March is wrong in September, and a calculator that hides when it last looked is worse than no calculator.
Nothing here calls an API, so nothing here can leak a collection list, a device, or an email address. Tools that remember your input — the collection tracker, the subscription ledger — keep it in your own browser's storage and offer a CSV export so you are never locked in.