VESA Timing Calculator

Estimate display timing totals from active pixels, porch and sync intervals, CVT reduced-blanking style estimates, refresh rate, pixel clock, scan rates, and common VESA display-interface limits.

🎯Real VESA timing presets

Presets are editable planning modes. Exact VESA/EDID timings can vary by panel, scaler, transport, and firmware, so use measured EDID values when available.

⚙Active raster and timing inputs

Timing method CVT-RB style values estimate reduced horizontal blanking and vertical blanking lines.

Target refresh rate (Hz) Enter exact rates such as 59.94, 60, 119.88, 120, 144, 165, or 240.

Active pixels

Horizontal

Vertical

Use active image pixels only, before porch, sync, and back-porch blanking are added.

Horizontal blanking intervals (pixels)

Front porch

Sync width

Back porch is entered separately so the calculator can show the full blanking split.

Horizontal back porch (pixels) Horizontal total = active + front porch + sync width + back porch.

Vertical blanking intervals (lines)

Front porch

Sync width

Vertical blanking controls frame period alongside the horizontal line total.

Vertical back porch (lines) Vertical total = active lines + front porch + sync width + back porch.

Display color format Color format estimates raw payload and helps compare the timing to display transports.

Display spec to compare Comparison is raw planning math; DSC, guard bands, audio/data islands, and device limits can change the final fit.

Custom pixel clock limit (MHz) Used for the clock verdict card, useful for scaler ICs, panels, bridges, and EDID caps.

Enter positive active pixels, refresh rate, porch/sync intervals, color format, and display-spec limits.

Timing is ready to calculate.

Estimated pixel clock

MHz from total pixels and refresh

Timing totals

horizontal total x vertical total

Blanking share

non-active timing overhead

Display spec fit

against selected interface

Full timing breakdown

📊Current timing spec summary

-- Active pixels/frame Image area before blanking intervals are added.

-- Horizontal scan Line rate derived from total vertical lines and refresh.

-- Raw video payload Color samples multiplied by total pixel rate.

-- Porch/sync model Current timing profile used by the calculator.

🖥VESA timing and display spec comparison grid

Display spec	Usable rate	Clock signal	Typical VESA timing fit
HDMI 1.4 TMDS	8.16 Gbps payload	340 MHz TMDS class	1080p120 or 4K30 with reduced chroma
HDMI 2.0 TMDS	14.4 Gbps payload	600 MHz TMDS class	4K60 8-bit 4:4:4 or 1440p144 near limit
DisplayPort 1.2 HBR2	17.28 Gbps payload	4 lanes, 8b/10b	4K60 8-bit, 1440p144 8-bit with tight timing
DisplayPort 1.4 HBR3	25.92 Gbps payload	4 lanes, 8b/10b	4K120 with DSC or 4K98 8-bit uncompressed class
HDMI 2.1 FRL 40	35.56 Gbps payload	16b/18b link coding	4K120 10-bit 4:4:4 near the edge
HDMI 2.1 FRL 48	42.67 Gbps payload	16b/18b link coding	4K144 class or 8K60 with DSC
eDP 1.4 HBR3 x4	25.92 Gbps payload	Embedded panel link	High-res laptop panels, often with PSR or DSC

📚Reference tables

Reduced blanking planning values

Profile	H blank	V blank	Best use
CVT-RB v1 style	160 pixels	20 to 35 lines	Older PC LCD monitor modes
CVT-RB v2 style	80 pixels	32 to 63 lines	Modern high-refresh LCD timing estimates
CTA / CEA style	5% to 12%	20 to 45 lines	TV-focused video modes and HDMI sinks
Manual EDID	Exact values	Exact values	Panel datasheet, EDID, or measured modeline

Porch and sync formulas

Timing item	Formula	Unit	Meaning
Horizontal blanking	HFP + HS + HBP	pixels	Non-active pixels per line
Vertical blanking	VFP + VS + VBP	lines	Non-active lines per frame
Pixel clock	HTotal x VTotal x Hz	MHz	Total sampled pixels per second
Horizontal scan	VTotal x Hz	kHz	Lines scanned per second
Frame period	1000 / Hz	ms	Time for one complete frame

Common timing examples

Mode	Total estimate	Clock class	Notes
1920x1080 60 RB	2080 x 1111	138.6 MHz	Common PC monitor reduced blanking class
2560x1440 144 RBv2	2640 x 1481	563 MHz	Often close to HDMI 2.0 limits at 8-bit
3440x1440 144 RBv2	3520 x 1481	751 MHz	Usually needs DP, FRL, or compression
3840x2160 60 RBv2	3920 x 2223	523 MHz	4K60 fits modern links with reduced timing
3840x2160 120 RBv2	3920 x 2223	1046 MHz	High-bandwidth source and sink required

Color payload factors

Format	Bits/pixel	Use	Effect
RGB 8-bit	24 bpp	PC SDR	Baseline full chroma
RGB 10-bit	30 bpp	HDR desktop	25% more than 8-bit RGB
RGB 12-bit	36 bpp	Deep color	50% more than 8-bit RGB
YCbCr 4:2:2 10-bit	20 bpp	Video links	Saves one-third vs RGB 10-bit
YCbCr 4:2:0 10-bit	15 bpp	TV fallback	Half of RGB 10-bit payload

💡Timing tips

Compare totals, not just active pixels. A display mode is transported using horizontal total times vertical total times refresh. Two 3840 x 2160 modes can have meaningfully different pixel clocks if their porch and sync intervals differ.

Use EDID or panel datasheet values for final work. CVT-RB-style estimates are useful for planning, but real sinks can require exact sync polarity, minimum blanking lines, clock tolerance, or a published modeline.

A timing calculator is use to determine the values of timing that are required for a display to work correctly. If your monitor or embedded panel displays does not lock to the display, then it is likely that the timing for that display is incorrect. Every display require the pixels to be active at the proper time, with the proper porch and sync interval.

If the timing for a display is incorrect, then the image will display in a scramble fashion; if it is correct, the image will be displayed in a clean fashion. A timing calculator can help to convert the specifications of a display into the timing values that are required to configure that display properly. The first of the values that you can enter into a timing calculator is the active raster of the display.

How to Use a Display Timing Calculator

The active raster includes the width and the height of the visible portion of the display. The active raster is the portion of the display that is visible to the user of the display; it does not include any blanking area for sync signals. If the dimensions of the active raster are altered, then each of the values for timing that the display calculates will change, as well.

For instance, active rasters of 1920 by 1080 will be different than active rasters of 2560 by 1440 due to the fact that the 2560 by 1440 display includes more pixel. The timing profile that is used with the active raster will help to calculate the horizontal and vertical total for the display. The pixel clock for the display will be calculated from these horizontal and vertical totals, rather than from the active raster value.

Porch intervals and sync intervals will be required for the display. The horizontal front porch will allow for the beam to stabilize before the sync signal to arrive at the display, and the horizontal back porch will allow for the display receiver to prepare for the next line of the display. Even moddern flat panel displays require each of these intervals; devices like scalers, transmitters, and receivers require these sync signal to function properly.

These settings can be switched between CVT reduced blanking profiles and traditional video profile. Reduced blanking profiles reduce the size of the porch and sync intervals; this can save bandwidth for the display link. However, using such a profile can create issues for the displays with a sink that requires sync signals of a specific width or polarity.

For these displays, if any image rolling or sparkles are seen after switching to the reduced blanking profile, it may be necessary to check whether the sink has accepted the updated horizontal and vertical totals. The timing calculator will display the pixel clock as one of the main output from the timing calculator. The pixel clock is measured in megahertz, and will indicate whether a specific link to the display, such as HDMI 2.0 or DisplayPort 1.4, can support the selected display mode.

For instance, HDMI 2.0 may have a limit of 600 megahertz for its TMDS clock; if the calculated pixel clock exceeds this value, it may be necessary to reduce the color depth of the image. In addition to the pixel clock, the timing calculator may also provide an estimate of the raw payload of the display link in gigabits per second. For example, using a ten-bit RGB color format will result in a display link that has 25% more data to transmit than one that is using an eight-bit RGB color format; thus, a ten-bit color format will require more bandwidth to transmit the image properly.

The refresh rate is one of the main component of timing calculations. For example, a refresh rate that works for a display mode at 60 hertz may not allow for the same display at 144 hertz; the refresh rate for the display will multiply the horizontal and vertical totals. Thus, refresh rates in the form of 59.94 or 119.88 can be entered.

Additionally, the horizontal scan rate can be calculated in kilohertz; this value is useful for displays with a line rate limit for the panel; if the calculated value is too high, the panel may refuse the mode. In most instance, the specifications that the timing calculator calculates will not match the actual displays from the hardware device that is connected. As the signal travels from the source to the sink, any cables will introduce jitter into the signal, the transmitter will output the signal with a degree of tolerance, and the receiver will require additional line for blanking.

Additionally, older embedded panels may not include these specifications in their description of the panels. Thus, fields for entering a custom pixel clock limit for the hardware device can be provided; the pixel clock for any scaler or bridge chip can be entered into this field. This field is also helpful for older embedded panels, as it is one of the only specification that may be listed for the panel.

Color formats may change the payload of the data that is sent along the display link. For example, if a four-two-two sampling format is used, the horizontal chroma resolution will be halved, and the data rate will be halved, as well. By displaying these value for the payload in various color formats, the user can decide whether the bandwidth savings for a four-two-two format are worth any potential loss of color quality from the display.

Additionally, the timing calculator will not display the way the image will appear on the display, but it will indicate whether the link has the capability to carry the chosen color format. Comparison table can be provided to the user, listing the amount of usable payload that the link can transmit in various example of display interfaces. These table will also include information regarding the clock class of the link.

Both of these value will help the user to compare the calculated values to the display link that is being used. For both categories of values, the tables will note that the throughput of the link may be less under real world application than what is published for that link; audio data, metadata, and guard bands for the display links may reduce the available throughput of the link to the display device. An error that is common among those that use these timing calculators is assuming that the active resolution of the display is the only important factor.

For example, an individual may enter an active resolution of 3840 x 2160 into the calculator, but not consider whether the other factor will allow for the link to support such a display. Another of the common errors is copying the porch intervals and sync intervals from one profile to another without ensuring that they are the same for both profile. These value will be displayed on the calculator, allowing for any difference between the profiles to be noted before the timing is entered into the display device’s firmware.

Timing is a negotiation between the source device, the link between the devices, and the sink device; a timing calculator provide the numbers to that negotiation. Beyond entering the horizontal and vertical totals, the other values can be entered into the firmware of the display device; however, it is also recommended to enter the horizontal and vertical totals into the display device’s EDID. Measured value for the sink will be more accurate than the estimates provided by the timing calculator, but these estimate will help an individual to determine which display mode they should test on the display device.