eSIM & Travel Data Plan Calculator
Calculate the mobile data you need abroad and compare costs of eSIM, local SIM, and roaming for any destination and trip length.
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Travel Data Guide
What do I need to know about eSIMs Explained?
An eSIM is a digital SIM card built into your phone — no physical SIM swap needed. Activate by scanning a QR code in seconds. Supported on: iPhone XS and newer (XR, 11, 12, 13, 14, 15, all SE except first gen). Most Android flagships from 2020+ (Samsung S20+, Google Pixel 3+). Many phones support dual SIM (physical + eSIM) — keep your UK number active for SMS while using local data on eSIM. Major eSIM providers: Airalo (cheapest, widest coverage). Holafly (unlimited plans, premium pricing). Sail Wi-Fi and other providers also offer eSIM plans, though pricing and coverage vary significantly, so comparing a few options before travel is worthwhile.
What's the difference between Roaming and eSIM vs Local SIM?
UK roaming costs (2024): EU — most networks now include free roaming up to 25GB after 'Brexit reintroduction.' EE, Three, Vodafone: free in EU on most plans. USA/global — fees apply: EE: £6/day for £25 daily passes. Three Go Roam Around the World: 71 countries, often included. Vodafone: £8/day standard plans, £6.85/day for premium plans. Local SIM costs: Thailand: £5-15 for 7-30 days unlimited 4G/5G. Japan: £20-40 for tourist SIM. USA: £30-50 for 30 days, more expensive due to high local data prices generally, even for tourist-focused SIM and eSIM plans.
What's the key thing to understand about Estimating Data Usage?
Typical app data usage per hour: Google Maps navigation: 5-10MB/hour. Instagram browsing: 100-200MB/hour. TikTok or YouTube standard: 250-500MB/hour. YouTube HD: 1-2GB/hour. Netflix streaming: 1-3GB/hour SD/HD/4K. Video calls (Zoom, FaceTime): 500MB-1.5GB/hour. WhatsApp messaging: <10MB/hour. WhatsApp voice calls: 1.5MB/min (~90MB/hour). Email: 1-10MB/hour. Daily totals: light traveller — 300-500MB. Moderate — 1-2GB. Heavy (streaming + work) — 3-5GB+. Data-saving tips: download offline maps before travelling, since navigation apps can otherwise use a surprising amount of data when constantly refreshing your live location.
What should I know about Practical Setup?
Before travel: check phone is unlocked (network-locked phones may not accept other SIMs). Buy eSIM 1-2 days before travel for safety. Test airplane mode + connecting via Wi-Fi to ensure setup works. Activate eSIM AT DESTINATION (not at home — many activate on first connection to local network). Keep your UK SIM as secondary for SMS (banking codes, two-factor authentication). Switch data setting to eSIM only. Most travel scenarios: keep UK plan for SMS only, use eSIM for data. Avoid: turning on roaming data on your home SIM alongside an active eSIM, since this can lead to accidentally using expensive roaming data instead of the cheaper eSIM plan you've paid for.