A small utility to help converting between dips and pixels in your Android code. Most solutions are unreadable, this one should read a lot better.

Dimens.java

import android.content.res.Resources;
import android.support.annotation.NonNull;
import android.util.DisplayMetrics;
import android.util.TypedValue;

/**
 * Convert between DP and pixels, like {@link java.util.concurrent.TimeUnit} does.
 * For example:
 * Dimens.DP.toPX(context.getResources(), 16);  // 16dp to pixels
 * Dimens.PX.toDP(context.getResources(), 16);  // 16px to dips
 */
public enum Dimens {

    DP {
        public int toPX(@NonNull final Resources resources, int dp) {
            return (int) TypedValue.applyDimension(
                    TypedValue.COMPLEX_UNIT_DIP, dp, resources.getDisplayMetrics());
        }

        public int toDP(@NonNull final Resources resources, int dp) {
            return dp;
        }
    },
    PX {
        public int toPX(@NonNull final Resources resources, int px) {
            return px;
        }

        public int toDP(@NonNull final Resources resources, int px) {
            DisplayMetrics metrics = resources.getDisplayMetrics();
            return (int) (px / ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT));
        }
    };

    Dimens() {
    }

    public int toPX(@NonNull final Resources resources, int value) {
        throw new AbstractMethodError();
    }

    public int toDP(@NonNull final Resources resources, int value) {
        throw new AbstractMethodError();
    }
}

Dimens2.java

import android.content.res.Resources;
import android.support.annotation.NonNull;
import android.util.DisplayMetrics;
import android.util.TypedValue;

/**
 * Convert between DP and pixels, like {@link java.util.concurrent.TimeUnit} does.
 * But now without enums, because #perfmatters
 * For example:
 * Dimens2.DP.toPX(context.getResources(), 16);  // 16dp to pixels
 * Dimens2.PX.toDP(context.getResources(), 16);  // 16px to dips
 */
public class Dimens2 {

    public static class DP {
        
        DP() {
        }
        
        public static float toPX(@NonNull final Resources resources, int dp) {
            return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, resources.getDisplayMetrics());
        }
        
        public static float toDP(@NonNull final Resources resources, int dp) {
            return dp;
        }
        
    }
    
    public static class PX {
    
        PX() {
        }
    
        public static float toPX(@NonNull final Resources resources, int px) {
            return px;
        }
    
        public static float toDP(@NonNull final Resources resources, int px) {
            DisplayMetrics metrics = resources.getDisplayMetrics();
            return px / ((float)metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT);
        }
    
    }

    Dimens() {
    }

}