1. Good (G): A 1919 wheat head penny in good condition, showing significant wear and tear, may be worth around $0.50 to $1.
2. Very Good (VG): A coin in very good condition, with signs of wear but still retaining some original details, may be worth $1 to $2.
3. Fine (F): A 1919 wheat head penny in fine condition, with moderate wear and distinct details visible, can be valued between $2 and $4.
4. Very Fine (VF): Coins in very fine condition, with minimal wear and most of the original details preserved, can fetch anywhere from $4 to $8.
5. Extremely Fine (XF): Extremely fine specimens exhibit little to no wear, with sharp details and a lustrous surface. These can be valued between $8 and $15.
6. Uncirculated (UNC): Uncirculated coins have never been in circulation and are in mint state, with no wear or blemishes. A 1919 wheat head penny in uncirculated condition can be worth anywhere from $15 to over $100, depending on its grade and rarity.
Rare varieties or errors of the 1919 wheat head penny can also command significantly higher values among coin collectors. It's always recommended to consult with a professional coin dealer or numismatic expert to accurately assess the value of your specific coin.