Add water and sugar to a saucepan on high heat and stir until sugar is dissolved. Heat until boiling.
Add sliced strawberries. Return mixture to a boil, then lower heat and simmer until strawberry pieces are very soft and shapeless, about 30 minutes.
Strain liquid into a storage container. You can stir the pulp to release juice but don't press on it. Reserve strawberry pulp for yogurt or baking if desired.
Refrigerate until used.
Notes
Makes about 2 cups, depending on how much water boils out. The resulting syrup can be canned by processing for 10 minutes in a boiling water bath. You will want to double (at least) the recipe to make enough to can.
I am not a health professional and nutrition data is calculated programatically. Accuracy may vary with product selection, calculator accuracy, etc. Consult a professional for the best information.