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Sizing an eSIM for a three-month stay

Data to plan for across 90 days at three levels of use, and which plan shape works out better at this trip length.

Author: Porsch Kunnipat Siramanakul · Co-founderReviewed by: Bob Kanokphon Thongdee
Sizing an eSIM for a three-month stay

Quick answer

  • For 90 days: about 91GB at normal use, 41GB if light, 193GB if heavy.
  • The numbers come from a fixed formula plus a 15 percent buffer, not from measuring your own use.

How much data 90 days needs

The figures below take three levels of daily use, multiply by the number of days, and add 15 percent for app updates and photo backup — the two things travellers forget.

Level of useRoughly per dayTotal for 90 days
Light: maps, chat, email0.4GB41GB
Normal: social, photos, short video0.9GB91GB
Heavy: streaming, video calls, hotspot1.9GB193GB
Sizing an eSIM for a three-month stay

The plan shape that fits this length

At 90 days we would start with a long-stay plan, or a local SIM, because that is where price per gigabyte and the risk of wasted data balance out. If your usage is uneven, weigh the top-up terms as well.

These are estimates from a fixed formula, not measurements of your own use. If you have data figures from a previous trip, trust those first.
Sizing an eSIM for a three-month stay

What people forget when sizing by days

Multiplying days by daily use gets you close, but real trips are lumpy. Day one is usually the heaviest — navigating, checking in, messaging home — while a day on a tour or a long transfer can use almost nothing.

  • The first and last days run above average; keep that in mind
  • Travelling as a pair on one hotspot means budgeting for two people, not one
  • Turning off automatic photo backup over mobile data, and syncing on Wi-Fi instead, is the single biggest saving available

FAQ

When does the 90-day clock start?+

Most plans start counting at first connection to a network at the destination, not at payment — but some count from the purchase date. Check the activation-policy line on the plan page before buying weeks ahead.

Should I buy exactly 90 days or add a buffer?+

Add at least one day. Delays, layovers and the trip home routinely spill past midnight, and a plan that expires while you are still at the airport leaves you offline exactly when you need it.

Daily or fixed data at this trip length?+

At 90 days the deciding factor is consistency. Even daily use suits a daily plan, which caps the cost predictably. Spiky use — heavy some days, nothing on others — suits a fixed-data pool.

About the author

Porsch Kunnipat Siramanakul

Porsch Kunnipat Siramanakul

  • Co-founder of eSIMonline.asia
  • Digital marketer
  • Performance marketing and marketing planning
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Plans that cover 90 days

Filtered to plans whose validity outlasts the trip and whose data clears the light-use estimate.

Turkey 50GB 180 days

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Fixed
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Yes
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Validity starts on first connection at the destination

  • One network
  • Conditions apply
from$25.90$24.60
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France 50GB 180 days

Orange

Fixed
Data
50GB
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Yes
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  • 5G ready
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Validity starts on first connection at the destination

  • One network
from$34.90$33.15
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Greece 50GB 180 days

Wind / Vodafone

Fixed
Data
50GB
Validity
180 days
Hotspot
Yes
Technology
3G / 4G / 5G
  • 5G ready
  • Hotspot
  • Top-up ready

Validity starts on first connection at the destination

from$34.90$33.15
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Belgium 50GB 180 days

Proximus / Orange / Base

Fixed
Data
50GB
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180 days
Hotspot
Yes
Technology
3G / 4G / 5G
  • 5G ready
  • Hotspot
  • Top-up ready

Validity starts on first connection at the destination

from$34.90$33.15
Details

Austria 50GB 180 days

3 / A1.net

Fixed
Data
50GB
Validity
180 days
Hotspot
Yes
Technology
3G / 4G / 5G
  • 5G ready
  • Hotspot
  • Top-up ready

Validity starts on first connection at the destination

from$34.90$33.15
Details

Denmark 50GB 180 days

TDC / 3

Fixed
Data
50GB
Validity
180 days
Hotspot
Yes
Technology
3G / 4G / 5G
  • 5G ready
  • Hotspot
  • Top-up ready

Validity starts on first connection at the destination

from$34.90$33.15
Details

Ireland 50GB 180 days

Eir

Fixed
Data
50GB
Validity
180 days
Hotspot
Yes
Technology
3G / 4G / 5G
  • 5G ready
  • Hotspot
  • Top-up ready

Validity starts on first connection at the destination

  • One network
from$34.90$33.15
Details

Germany 50GB 180 days

O2 / Vodafone

Fixed
Data
50GB
Validity
180 days
Hotspot
Yes
Technology
3G / 4G / 5G
  • 5G ready
  • Hotspot
  • Top-up ready

Validity starts on first connection at the destination

from$34.90$33.15
Details

Hungary 50GB 180 days

Telenor Hungary / Vodafone

Fixed
Data
50GB
Validity
180 days
Hotspot
Yes
Technology
3G / 4G / 5G
  • 5G ready
  • Hotspot
  • Top-up ready

Validity starts on first connection at the destination

from$34.90$33.15
Details