calculator.io

.io crawl

First seen 2026-04-13 · Last seen 2026-05-20 · ok HTTP/1.1 200 585 ms crawled 2026-05-06

US · 172.67.72.174 · AS13335 Cloudflare, Inc.

Reputation 97/100 dmarc monitor-only

Classifying

HTML metadata

Title

Calculator+iO — Online Calculators for Fitness, Science, Math, Finance, Health

Description

Find the calculator you need with our extensive collection of free online calculators! We've got you covered from finance to math, health to physics. Try it now!

Language

Canonical

https://www.calculator.io/

Translations

Open Graph

url: https://www.calculator.io/
title: Calculator+iO — Online Calculators for Fitness, Science, Math, Finance, Health
locale: en
site name: Calculator.iO
determiner: the
description: Find the calculator you need with our extensive collection of free online calculators! We've got you covered from finance to math, health to physics. Try it now!
locale:alternate: vi

Technology

CDN: Cloudflare

Analytics

Google Tag Manager

Ads

Google AdSense

Third-party hosts loaded (2)

pagead2.googlesyndication.com×1
www.googletagmanager.com×1

Social

DNS records live

NS

maria.ns.cloudflare.com
miles.ns.cloudflare.com

MX

12 route1.mx.cloudflare.net
38 route2.mx.cloudflare.net
78 route3.mx.cloudflare.net

TXT

hosting-site=calculator-io-db8f2

Verified for

Google

Email authentication strong

SPF: v=spf1 a mx include:_spf.google.com include:_spf.mx.cloudflare.net ~all
softfail (~all)
DMARC: v=DMARC1; p=none; aspf=r; adkim=s; rua=mailto:ff87c0530bd14fad99230d86c6b85f8c@dmarc-reports.cloudflare.net
policy: none (monitoring only)
DKIM: no key found at common selectors

Certificate (current)

WE1

from 2026-03-12 to 2026-06-10

Expires in 21 days

Full certificate history on crt.sh ↗

HTTP security headers

Header hygiene 50/100 Checked live page: https://www.calculator.io/

present

strict-transport-security

findings

missing Content Security Policy
missing frame protection
missing content type protection
missing Referrer Policy
missing Permissions Policy

Header values

strict-transport-security: max-age=31556926