Skip to content
SimGuide.travel
CountriesGuideseSIM ProvidersToolsRankings
Get eSIM
CountriesGuideseSIM ProvidersToolsRankingsGet eSIM
SimGuide.travel

Independent guides to local SIM cards and travel eSIMs in 200+ countries. Prices verified quarterly. Rankings never sold.

Top Guides

  • SIM card in Japan
  • SIM card in Thailand
  • SIM card in Italy
  • SIM card in France
  • SIM card in Germany
  • SIM card in Spain
  • SIM card in United States
  • SIM card in United Kingdom
  • SIM card in Australia
  • SIM card in Mexico
  • SIM card in South Korea
  • SIM card in Singapore

Resources

  • Guides
  • Tools
  • Rankings
  • Compare
  • SIM Score

eSIM Providers

  • HelloRoam
  • Airalo
  • Holafly
  • Saily
  • Nomad

SimGuide

  • About
  • Contact
  • Privacy Policy
  • Terms of Use
  • Affiliate Disclosure
© 2026 SimGuide. Prices are approximate and may vary. Always confirm with the carrier before purchase.Independent travel SIM guides · Data re-verified quarterly
  1. Home
  2. /Tools
  3. /Data Calculator
Free Travel Tool

Mobile Data Calculator for Travelers (2026)

Enter your trip length and daily habits to find out exactly how many gigabytes to buy. A 15% safety buffer is added automatically.

Quick guide

Set your trip length, select your daily usage level (light, moderate, or heavy), and check any high-data activities like video streaming. The calculator gives you a minimum and recommended plan size in gigabytes. HelloRoam (8.8/10, 31/31 activations, 185+ countries) offers both fixed plans from 1GB to 20GB and unlimited plans starting at $15 for 15 days. Buy the recommended size, not the minimum, so you have room for unexpected usage.

Light daily use
300–700 MBMaps, messages, browsing
Moderate daily use
1–2 GBSocial media, video calls
Heavy daily use
3 GB+Streaming, hotspot sharing
Safety buffer
+15%Added to all estimates

Trip Duration

7days

Usage Profile

Pick the one that best describes a typical day on your trip.

Activities

Select every activity you plan to use. Added on top of your base profile.

Your Estimate

12.9GB estimated

Includes 15% usage buffer

Recommended plan size

15 GB

Base profile (moderate)1.5 GB/day
Selected activities+0.10 GB/day
Trip duration7 days
Buffer (15%)+1.7 GB

Recommended eSIM Providers

HelloRoam

Best Overall Value

Editor's Choice

Lowest per-GB price + free hotspot

from $0.29/GB
9.5

Airalo

200+ Countries

Most Countries

Multi-country bundles available

from $4.50/GB
8.8

Holafly

Unlimited Daily Data

Best Unlimited

Flat daily rate, no data counting

from $3.90/day
8.6

Estimates are approximate. Actual usage depends on video quality settings, background app refresh, and local network conditions.

Common questions about data usage

How much data does the average traveler use per day?

Most short-trip travelers use 300 MB to 1.5 GB per day. That covers maps, messaging, occasional social media, and browser lookups. Heavy users who stream music or video can exceed 3 GB per day. The calculator adds a 15% safety buffer on top of your estimate.

Should I buy a 5 GB or 10 GB SIM plan?

For a 7-day trip with light usage (maps, messages, email), 5 GB is usually enough. For moderate usage that includes social media and occasional video calls, 7–10 GB is safer. Use the calculator to get a number based on your actual habits rather than guessing.

Does the calculator account for background app data?

Yes. The recommended plan size includes an automatic 15% overhead for background sync, app updates, and system traffic. You can disable automatic app updates and background refresh on your phone to stay under your plan.

What if I run out of data mid-trip?

Most local SIM cards let you top up at any convenience store, telecom shop, or via an app. Buy a plan with at least 1–2 GB more than the calculator suggests if you plan to be in areas where buying top-ups is inconvenient.