In general, favour items that use more bars to achieve faster experience rates. GP/XP for individual items can be found here.
The Knight's Sword is a free-to-play quest that gives 12,725 Smithing experience upon completion. This reward would elevate a level 1 smith to level 29 immediately. It is strongly recommended that people do this quest before training Smithing. For ironmen to obtain the iron bars, head to the trees located in level 18 Wilderness next to the bears west of the Graveyard of Shadows.
If questing isn't your thing and you'd prefer straight smithing, bronze bars provide 6.2 experience upon creation of a bar in the forge. Every bar of bronze used in the process of forging weapons or armour will grant you 12.5 experience.
Levels 29-33 - bronze platebodies
Forge bronze platebodies to level 33.
- Experience needed - 6,216
- Bronze bars needed - 500
- Bronze bars cost = 69,500
- Bronze platebodies = 2,400
- Total profit = -67,100 (-115 each)
- Tin & Copper ores needed - 335 each
- Tin ores cost = 14,740
- Copper ores cost = 16,080
- Total ore cost = 30,820
- Bronze platebodies = 1,608
- Total profit = -29,212 (-436 each)
Level 33-48 - iron platebodies
Iron platebodies are the fastest experience after bronze platebodies, giving twice as much experience at 125 per.
- Experience needed - 64,767
- Iron bars needed - 2,595
- Iron bars cost = 674,700
- Iron platebodies = 55,014
- Total profit = -619,686 (-1,194 each)
- Iron ores needed (assuming 50% success rate) - 3,460
- Iron ores cost = 515,540
- Iron platebodies = 36,676
- Total profit = -478,864 (-1,384 each)
Level 48-68 - steel platebodies
Steel platebodies provide the highest experience per item at 187.5 XP per and should be forged until level 68.
- Experience needed - 522, 018
- Steel bars needed - 13,925
- Steel bars cost = 7,394,175
- Steel platebodies = 2,645,750
- Total profit = -4,748,425 (-1,705 each)
- Iron ore needed - 9,494
- Iron ores cost = 1,414,755
- Coal needed - 18,990
- Coal cost = 4,177,800
- Steel platebodies = 1,804,050,.
- Total profit = -3,788,505 (-1,995 each)
Level 68-88 - mithril platebodies
Mithril platebodies overtake steel platebodies in terms most experience provided at level 68 with 250 XP. They are the fastest experience to level 88. You can expect xp rates of 150k - 176k xp p/hr depending on focus.
- Experience needed - 3,780,744
- Mithril bars needed - 75,615
- Mithril bars cost = 63,894,675
- Mithril platebodies = 42,314,154
- Total profit = -21,580,521 (-1,427 each)
- Mithril ores needed - 47,260
- Mithril ores cost = 8,223,240
- Coal needed - 189,040
- Coal cost = 41,588,800
- Total ore cost = 49,812,040
- Mithril platebodies = 26,446,696
- Total profit = -23,365,344 (-2,472 each)
Level 88-99 - adamant platebodies
Adamant platebodies are the fastest and cheapest method to reach 99 Smithing in free-to-play at 312.5 XP each. This provides around 215,000 xp/hour with use of energy potions.
- Experience needed - 8,648,655
- Adamant bars needed - 138,380
- Adamantite bars cost = 283,125,480
- Adamant platebodies = 265,440,516
- Total profit = -17,684,964 (-639 each)
- Adamantite ores needed - 86,490
- Adamantite ores cost = 89,517,150
- Coal needed - 518,940
- Coal cost = 114,166,800
- Total ore cost = 203,683,950
- Adamant platebodies = 165,905,118
- Total profit = -37,778,832 (-2,184 each)
After level 99, rune armour becomes available to smith which will provide the best experience and turn a profit if the items are sold on the Grand Exchange. This is due to their high alch prices and popularity with free-to-play player-killers.
Superheating ores while training mining, then dropping the bars will give you experience in Smithing at a relatively low cost. Superheating ores off the Grand Exchange is generally expensive and other methods of training are faster.