Cover Size

{
  "asOf": "2026-10-12T01:40:24.622Z",
  "bleedIn": 0.125,
  "coverHeightIn": 9.25,
  "coverHeightMm": 234.95,
  "coverHeightPx": 2775,
  "coverWidthIn": 12.9256,
  "coverWidthMm": 328.31,
  "coverWidthPx": 3878,
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "dpiUsed": 300,
  "frontXStartIn": 6.8006,
  "inputUnit": "in",
  "notChecked": [
    "your printer's own cover template (spine rounding, safe margins, barcode zone and wrap rules differ)",
    "hardcover wrap, board and hinge allowances, which add more than bleed",
    "…1 more"
  ],
  "reasons": [
    "Width = back trim + spine + front trim + bleed on both outer edges; height = trim height + bleed top and bottom.",
    "Spine: 300 pages x 0.002252 in (black ink on white paper (common POD figure 0.002252 in per page))."
  ],
  "source": "computed locally (width = back + spine + front + 2 bleed; height = trim + 2 bleed)",
  "spineWidthIn": 0.6756,
  "spineXStartIn": 6.125,
  "summary": "Full cover is 12.9256 x 9.25 in (328.3 x 235 mm) with a 0.6756 in spine.",
  "trimHeightIn": 9,
  "trimWidthIn": 6,
  "verdict": "COMPUTED"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://publishing-calc.x402tookit.com/cover-size?pages=300&paper=white&trimHeight=9&trimWidth=6'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://publishing-calc.x402tookit.com/cover-size?pages=300&paper=white&trimHeight=9&trimWidth=6' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fpublishing-calc.x402tookit.com%2Fcover-size
const res = await pay("https://publishing-calc.x402tookit.com/cover-size?pages=300&paper=white&trimHeight=9&trimWidth=6");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://publishing-calc.x402tookit.com/cover-size?pages=300&paper=white&trimHeight=9&trimWidth=6")
    print(res.status_code, res.text)