Free Tool

Bluetooth LE Throughput Calculator

Model theoretical data throughput for any Bluetooth LE connection. Adjust PHY, connection interval, DLE, MTU, and encryption to see the impact on data rate.

4 PHY modes iOS & Android presets Step-by-step breakdown

Scope: This calculator models classic Bluetooth LE connections using the standard 7.5 ms–4,000 ms Connection Interval range (Core Spec Vol 6, Part B, Section 4.5.1). It does not account for newer specification features:

Connection Subrating (Bluetooth 5.3) — dynamically skip connection events without renegotiating parameters
Sub-millisecond Connection Intervals (Bluetooth 6.0) — CI values down to 375 microseconds
Channel Sounding / HADM (Bluetooth 6.0) — high-accuracy distance measurement features that share radio time

Connection Parameters

PHY

Connection Interval

Data Length Extension (DLE)

Off — max 27 bytes per LL packet

ATT MTU

bytes

Encryption (MIC)

Off — no MIC overhead (unencrypted)

Encrypted connections add a 4-byte Message Integrity Check (MIC) to each data packet.

Calculation Control

Theoretical Max Packets/Event

Computed from floor(CI / Pair Time)

Packets/Event Cap (Optional)

Real devices often limit packets per connection event. Phones are the most common bottleneck — iOS typically caps at 4–7 packets.

Max Packets per Event

Leave empty for theoretical maximum. Set to model real-world device constraints.

Results

Theoretical Throughput

—

Capped Throughput

—

No cap applied

Application Payload / Packet

—

Pair Time (Data + ACK + IFS)

—

Step-by-Step Breakdown

Step	Calculation	Result

Real-World Reference

Implementation-specific parameters that affect actual throughput on phones and embedded controllers.

Parameter	iOS (iPhone)	Android 14+
ATT MTU	~244 bytes (iOS 18). Can support up to 527 but 244 is commonly observed.	517 bytes (forced by OS since Android 14)
MTU API control	None — iOS negotiates automatically	requestMtu() exists but Android 14 overrides to 517
Min connection interval	15 ms (11.25 ms for HID)	11.25 ms (AOSP default since ~Android 8)
2M PHY	Yes, automatic (iPhone 8+)	Yes, via setPreferredPhy()
Coded PHY	No (removed in iOS 14)	Chipset-dependent
DLE (max)	251 bytes (iPhone 7+)	251 bytes
Packets/event	~4–7	~6 (varies by chipset)
Max GATT throughput	~400–800 kbps	~700–1,400 kbps

The Bluetooth specification does not define a maximum number of packets per connection event — this is entirely implementation-specific.

Platform	Typical Pkts/Event	Configurable?	Notes
Nordic nRF	2–10+	Yes	GAP_EVENT_LENGTH + Connection Event Extension
Infineon CYW20829	4–6+ (est.)	Indirectly	Controller manages internally
TI CC26xx	Unlimited*	Yes	MAX_NUM_PDU (time-constrained only)
Silicon Labs EFR32	3–10+	Yes	max_ce_length (0.625 ms units)

Operation type also matters: Notifications/Write Commands allow multiple packets per event. Indications/Write Requests are limited to one ATT-level round-trip per event.

When MTU exceeds what a single LL packet can carry (247 bytes), L2CAP fragments across multiple LL packets. Choosing the right MTU avoids wasted space:

MTU 502: ATT PDU splits into exactly 2 full LL packets — 244 + 251 bytes of app data. No waste.

MTU 512: Requires 3 LL packets — 244 + 251 + only 10 bytes in the third. Nearly a full packet wasted.

This is why MTU 502 is often recommended over 512 for maximum throughput efficiency.

Phone Parameters

Embedded Controllers