I can’t take credit for this one. The credit goes to my friend Randolph. His post is at https://bornsql.ca/s/memory/ . He even has a script that will do it for you.
This leaves some ram for Windows to use and I’ve found its a good map to follow for production servers.
| RAM Installed in System | Max Server Memory |
|---|---|
| 4 GB | 2 GB |
| 8 GB | 5 GB |
| 12 GB | 8 GB |
| 16 GB | 11 GB |
| 20 GB | 14 GB |
| 24 GB | 18 GB |
| 28 GB | 21 GB |
| 32 GB | 25 GB |
| 36 GB | 28 GB |
| 40 GB | 32 GB |
| 44 GB | 35 GB |
| 48 GB | 39 GB |
| 52 GB | 42 GB |
| 56 GB | 46 GB |
| 60 GB | 49 GB |
| 64 GB** | 53 GB |
| 68 GB | 56 GB |
| 72 GB | 60 GB |
| 76 GB | 63 GB |
| 80 GB | 67 GB |
| 84 GB | 70 GB |
| 88 GB | 74 GB |
| 92 GB | 77 GB |
| 96 GB | 81 GB |
| 100 GB | 84 GB |
| 104 GB | 88 GB |
| 108 GB | 91 GB |
| 112 GB | 95 GB |
| 116 GB | 98 GB |
| 120 GB | 102 GB |
| 124 GB | 105 GB |
| 128 GB** | 109 GB |
| 132 GB | 112 GB |
| 136 GB | 116 GB |
| 140 GB | 119 GB |
| 144 GB | 123 GB |
| 148 GB | 126 GB |
| 152 GB | 130 GB |
| 156 GB | 133 GB |
| 160 GB | 137 GB |
| 164 GB | 140 GB |
| 168 GB | 144 GB |
| 172 GB | 147 GB |
| 176 GB | 151 GB |
| 180 GB | 154 GB |
| 184 GB | 158 GB |
| 188 GB | 161 GB |
| 192 GB | 165 GB |
| 196 GB | 168 GB |
| 200 GB | 172 GB |
| 204 GB | 175 GB |
| 208 GB | 179 GB |
| 212 GB | 182 GB |
| 216 GB | 186 GB |
| 220 GB | 189 GB |
| 224 GB | 193 GB |
| 228 GB | 196 GB |
| 232 GB | 200 GB |
| 236 GB | 203 GB |
| 240 GB | 207 GB |
| 244 GB | 210 GB |
| 248 GB | 214 GB |
| 252 GB | 217 GB |
| 256 GB | 221 GB |
| 260 GB | 224 GB |
| 264 GB | 228 GB |
| 268 GB | 231 GB |
| 272 GB | 235 GB |
| 276 GB | 238 GB |
| 280 GB | 242 GB |
| 284 GB | 245 GB |
| 288 GB | 249 GB |
| 292 GB | 252 GB |
| 296 GB | 256 GB |
| 300 GB | 259 GB |
| 304 GB | 263 GB |
| 308 GB | 266 GB |
| 312 GB | 270 GB |
| 316 GB | 273 GB |
| 320 GB | 277 GB |
| 324 GB | 280 GB |
| 328 GB | 284 GB |
| 332 GB | 287 GB |
| 336 GB | 291 GB |
| 340 GB | 294 GB |
| 344 GB | 298 GB |
| 348 GB | 301 GB |
| 352 GB | 305 GB |
| 356 GB | 308 GB |
| 360 GB | 312 GB |
| 364 GB | 315 GB |
| 368 GB | 319 GB |
| 372 GB | 322 GB |
| 376 GB | 326 GB |
| 380 GB | 329 GB |
| 384 GB | 333 GB |
| 388 GB | 336 GB |
| 392 GB | 340 GB |
| 396 GB | 343 GB |
| 400 GB | 347 GB |
| 404 GB | 350 GB |
| 408 GB | 354 GB |
| 412 GB | 357 GB |
| 416 GB | 361 GB |
| 420 GB | 364 GB |
| 424 GB | 368 GB |
| 428 GB | 371 GB |
| 432 GB | 375 GB |
| 436 GB | 378 GB |
| 440 GB | 382 GB |
| 444 GB | 385 GB |
| 448 GB | 389 GB |
| 452 GB | 392 GB |
| 456 GB | 396 GB |
| 460 GB | 399 GB |
| 464 GB | 403 GB |
| 468 GB | 406 GB |
| 472 GB | 410 GB |
| 476 GB | 413 GB |
| 480 GB | 417 GB |
| 484 GB | 420 GB |
| 488 GB | 424 GB |
| 492 GB | 427 GB |
| 496 GB | 431 GB |
| 500 GB | 434 GB |
| 504 GB | 438 GB |
| 508 GB | 441 GB |
| 512 GB | 445 GB |
| 516 GB | 448 GB |
| 520 GB | 452 GB |
| 524 GB | 455 GB |
| 528 GB | 459 GB |
| 532 GB | 462 GB |
| 536 GB | 466 GB |
| 540 GB | 469 GB |
| 544 GB | 473 GB |
| 548 GB | 476 GB |
| 552 GB | 480 GB |
| 556 GB | 483 GB |
| 560 GB | 487 GB |
| 564 GB | 490 GB |
| 568 GB | 494 GB |
| 572 GB | 497 GB |
| 576 GB | 501 GB |
| 580 GB | 504 GB |
| 584 GB | 508 GB |
| 588 GB | 511 GB |
| 592 GB | 515 GB |
| 596 GB | 518 GB |
| 600 GB | 522 GB |
| 604 GB | 525 GB |
| 608 GB | 529 GB |
| 612 GB | 532 GB |
| 616 GB | 536 GB |
| 620 GB | 539 GB |
| 624 GB | 543 GB |
| 628 GB | 546 GB |
| 632 GB | 550 GB |
| 636 GB | 553 GB |
| 640 GB | 557 GB |
| 644 GB | 560 GB |
| 648 GB | 564 GB |
| 652 GB | 567 GB |
| 656 GB | 571 GB |
| 660 GB | 574 GB |
| 664 GB | 578 GB |
| 668 GB | 581 GB |
| 672 GB | 585 GB |
| 676 GB | 588 GB |
| 680 GB | 592 GB |
| 684 GB | 595 GB |
| 688 GB | 599 GB |
| 692 GB | 602 GB |
| 696 GB | 606 GB |
| 700 GB | 609 GB |
| 704 GB | 613 GB |
| 708 GB | 616 GB |
| 712 GB | 620 GB |
| 716 GB | 623 GB |
| 720 GB | 627 GB |
| 724 GB | 630 GB |
| 728 GB | 634 GB |
| 732 GB | 637 GB |
| 736 GB | 641 GB |
| 740 GB | 644 GB |
| 744 GB | 648 GB |
| 748 GB | 651 GB |
| 752 GB | 655 GB |
| 756 GB | 658 GB |
| 760 GB | 662 GB |
| 764 GB | 665 GB |
| 768 GB | 669 GB |
| 772 GB | 672 GB |
| 776 GB | 676 GB |
| 780 GB | 679 GB |
| 784 GB | 683 GB |
| 788 GB | 686 GB |
| 792 GB | 690 GB |
| 796 GB | 693 GB |
| 800 GB | 697 GB |
| 804 GB | 700 GB |
| 808 GB | 704 GB |
| 812 GB | 707 GB |
| 816 GB | 711 GB |
| 820 GB | 714 GB |
| 824 GB | 718 GB |
| 828 GB | 721 GB |
| 832 GB | 725 GB |
| 836 GB | 728 GB |
| 840 GB | 732 GB |
| 844 GB | 735 GB |
| 848 GB | 739 GB |
| 852 GB | 742 GB |
| 856 GB | 746 GB |
| 860 GB | 749 GB |
| 864 GB | 753 GB |
| 868 GB | 756 GB |
| 872 GB | 760 GB |
| 876 GB | 763 GB |
| 880 GB | 767 GB |
| 884 GB | 770 GB |
| 888 GB | 774 GB |
| 892 GB | 777 GB |
| 896 GB | 781 GB |
| 900 GB | 784 GB |
| 904 GB | 788 GB |
| 908 GB | 791 GB |
| 912 GB | 795 GB |
| 916 GB | 798 GB |
| 920 GB | 802 GB |
| 924 GB | 805 GB |
| 928 GB | 809 GB |
| 932 GB | 812 GB |
| 936 GB | 816 GB |
| 940 GB | 819 GB |
| 944 GB | 823 GB |
| 948 GB | 826 GB |
| 952 GB | 830 GB |
| 956 GB | 833 GB |
| 960 GB | 837 GB |
| 964 GB | 840 GB |
| 968 GB | 844 GB |
| 972 GB | 847 GB |
| 976 GB | 851 GB |
| 980 GB | 854 GB |
| 984 GB | 858 GB |
| 988 GB | 861 GB |
| 992 GB | 865 GB |
| 996 GB | 868 GB |
| 1000 GB | 872 GB |
| 1004 GB | 875 GB |
| 1008 GB | 879 GB |
| 1012 GB | 882 GB |
| 1016 GB | 886 GB |
| 1020 GB | 889 GB |
| 1024 GB | 893 GB |
** Standard Edition supports a maximum of 64 GB RAM, for SQL Server 2012 and below. SQL Server 2014 Standard Edition and higher supports up to 128 GB RAM.