display timing calculator - Aaron Graves, PhDude Replica

Estimate pixel clock, scan rates, blanking overhead, and transport bandwidth for custom video timings.

Timing Preset

Refresh Rate (Hz)

Horizontal Active Pixels

Vertical Active Lines

H Front Porch (px)

H Sync Width (px)

H Back Porch (px)

V Front Porch (lines)

V Sync Width (lines)

V Back Porch (lines)

Bits per Pixel (bpp)

Transport Encoding

Enter timing values and click Calculate Timing.

Note: This is a mathematical timing calculator. Actual compatibility depends on signal standard, chroma subsampling, reduced blanking mode, DSC, and device-specific limits.

What a Display Timing Calculator Actually Tells You

A display timing calculator helps you convert a resolution and refresh rate into the underlying signal requirements: pixel clock, total line/frame timing, and approximate link bandwidth. This is useful when validating monitor overclocks, designing custom EDID timings, or checking if a cable/interface has enough headroom.

Key Timing Terms

1) Active Pixels

The visible image area. For 1920×1080, the active region is 1920 pixels wide by 1080 lines high.

2) Blanking Intervals

Blanking is non-visible timing around the active image. It includes:

Front porch
Sync pulse width
Back porch

These are included in total timing and directly increase required pixel clock and data rate.

3) Pixel Clock

Pixel clock is how fast pixels are transmitted, including blanking intervals. Even if your visible resolution stays fixed, larger blanking can increase clock frequency significantly.

Core Formulas Used

H_total = H_active + H_front_porch + H_sync + H_back_porch
V_total = V_active + V_front_porch + V_sync + V_back_porch
PixelClock(Hz) = H_total × V_total × RefreshRate
HorizontalScan(Hz) = PixelClock / H_total
FrameTime(ms) = 1000 / RefreshRate
RawDataRate(Gbps) = PixelClock × BitsPerPixel / 1e9
LinkRate(Gbps) = RawDataRate / EncodingEfficiency

Why This Matters in Practice

Custom resolutions: Quickly test if a timing is realistic before applying it.
Cable/interface planning: Compare required throughput against HDMI/DisplayPort limits.
Troubleshooting: Identify if blanking overhead is pushing bandwidth too high.
Panel tuning: Understand why two modes with similar refresh can have very different bandwidth requirements.

Bandwidth vs. Reality

The calculator outputs mathematical bandwidth demand. Real transport layers can add protocol overhead and constraints such as fixed lane rates, link training behavior, chroma subsampling (4:4:4 vs 4:2:2/4:2:0), and DSC compression. Use this result as a planning baseline, then verify with your GPU/monitor timing tool and standard-specific limits.

Quick Workflow

Start from a known-good preset (for example, 1080p60).
Adjust refresh first, then tighten blanking if needed.
Watch pixel clock and encoded link rate together.
Validate stability with real hardware testing.

Final Tip

If a mode fails unexpectedly, check blanking totals before reducing resolution. Small porch/sync changes can sometimes recover compatibility while preserving image quality and target refresh.