Japan Postage Calculator

Enter the sealed envelope’s size, thickness, and weight. The domestic letter price updates as you type.

Current result¥140Non-standard letter · standard sizeDetails ↓

Enter the envelope details

Estimate from the contents or use the exact weight.

Result updates instantly
Based on current Japan Post rates
No sign-up, no personal data
Exact weight gives the safest result

Japan domestic letter rates

These are the base prices before express, tracking, or registered-mail fees.

Fits a small envelope

Standard letter

¥110up to 50 g
  • 14–23.5 cm long
  • 9–12 cm wide
  • Up to 1 cm thick

Fits most A4 envelopes

Non-standard · standard size

Standard-size non-standard letter rates by weight
Up to 50 g¥140
Up to 100 g¥180
Up to 150 g¥270
Up to 250 g¥320
Up to 500 g¥510
Up to 1 kg¥750

Thicker or unusually shaped

Non-standard · oversized

Oversized non-standard letter rates by weight
Up to 50 g¥260
Up to 100 g¥290
Up to 150 g¥390
Up to 250 g¥450
Up to 500 g¥660
Up to 1 kg¥920
Up to 2 kg¥1,350
Up to 4 kg¥1,750

Which Japanese envelope do I have?

Look for these names on the package in a stationery shop or convenience store.

A4 folded in thirds

120 × 235 mm · about 5 g

A4 kept flat

240 × 332 mm · about 18 g

A4 close-fit envelope

228 × 312 mm · about 15 g

Why the estimate can change

One A4 sheet is estimated at 5 g and one clear file folder at 26 g. Real materials vary, so a kitchen scale or the post-office counter wins whenever you are close to a limit.

Need speed, tracking, or compensation?

Ordinary letters generally have no Saturday, Sunday, or public-holiday delivery. If you have a deadline, check Japan Post’s delivery-days lookup (Japanese) with the origin and destination postal codes before choosing a service. The price here does not promise an arrival date.

Delivery-day rules checked October 6, 2026: Japan Post’s weekend and holiday guidance and tracking-only service conditions.

速達

Express

+¥300

For letters up to 250 g. The surcharge rises for heavier items. Includes Saturday, Sunday, and holiday delivery.

特定記録

Tracking

+¥210

Records acceptance and provides online tracking. No compensation for loss or damage. Tracking alone does not add weekend or holiday delivery; selecting express as well does.

簡易書留

Simple registered

+¥350

Tracking plus compensation up to ¥50,000. Hand the item over at a post-office counter. Also delivered on weekends and holidays.

How to send with tracking (特定記録)

To use this option, take the envelope to a post-office counter and complete the 書留・特定記録郵便物等差出票 form available there. Keep the acceptance receipt. Adding the fee in stamps and dropping the envelope in a mailbox does not complete this procedure. Delivery is to the recipient’s mailbox, without a signature or seal, so choose a different service if you need signed receipt.

Japan Post’s tracking acceptance and delivery instructions (Japanese; checked October 16, 2026).

Common questions

Is postage the same anywhere in Japan?

Yes. The domestic letter rates shown here are nationwide. The destination does not change the price, but size, thickness, weight, and optional services do.

Can I trust the A4-sheet estimate?

Use it as a practical estimate only. Paper stock, envelopes, clips, and folders vary. If the result is near a weight boundary, weigh the sealed envelope or take it to a post office.

Can I put cash in an ordinary envelope?

No. Cash must be sent using Japan Post’s registered cash mail service (現金書留 / genkin kakitome) and its dedicated envelope.

Does this calculate international postage?

No. This calculator covers letters mailed within Japan. International letters use different zones, formats, and rates.

Independent calculator; not affiliated with Japan Post. Rates can change. The post-office counter has the final say for unusual items.